Engineering Innovations Volume 9

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Volume 9 of
Engineering Innovations
ISSN print 2813-0995
ISSN web 2813-1002

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Table of Contents

Influence of Annealing Duration on the Structural, Optical and Electrical Properties of ZnO Layers Deposited Using the Dip-Coating Method

May Zin Toe, Atsunori Matsuda, Khatijah Aisha Yaacob, Swee Yong Pung

Use of Polyacrylonitrile as Anodic Artificial Solid Electrolyte Interphase for Aqueous-Based Zinc-Ion Batteries

Nutchaya Muangplod, Anongnat Somwangthanaroj, Soorathep Kheawhom

Cathodized Stainless Steel Mesh for Binder-Free Layer Double Hydroxides Oxygen Evolution Reaction Electrode

Natthapon Sripallawit, Soorathep Kheawhom

Optimal Location of Capacitor in a Radial Distribution System Using New Hybrid Method

Hassane Ousseyni Ibrahim, Arouna Oloulade, Moussa Gonda, Francois Xavier Fifatin

Design and Implementation of Automatic Aiming and Locking System

Ping Cheng Chen, Chung Long Pan

System Dynamics Model to Improve Logistics Cost Efficiency in Fertilizer Distribution Outside Java (Gresik - Medan)

Yoke Candra Katon, Dhimas Widhi Handani, Ketut Buda Artana, Mikha Asta Lumirang, Putu Widhi Aprilia

Business Model Design for Cathode Material Manufacturer Startup Case Study: PT Polimikro Berdikari Nusantara

Dian Ahmad Pratama Bunayah Sudian, Wahyudi Sutopo, Muhammad Hisjam

Keywords Index

Authors Index

The original version of this eBook is available on https://www.scientific.net/book/engineering-innovations-vol-9/978-3-0364-1504-8

Engineering Innovations, ISSN: 2813-1002, Vol. 9, pp 1-13

doi: 10.4028/p-kCHUx4

© 2024 The Author(s). Published by Trans Tech Publications Ltd, Switzerland.

Submitted:
2023-01-16

Revised:
2023-01-20

Accepted:
2023-03-10

Online:
2024-02-12

Influence of Annealing Duration on the Structural, Optical and Electrical Properties of ZnO Layers Deposited Using the Dip-Coating Method

The original version of this paper is available on https://www.scientific.net/EI.9.1.pdf

May Zin Toe , Atsunori Matsuda , Khatijah Aisha Binti Yaccob and Swee-Yong Pung

School of Materials and Mineral Resources Engineering, Engineering Campus, Universiti Sains Malaysia, 14300 Nibong Tebal, Penang, Malaysia

Department of Electrical and Electronic Information Engineering, Toyohashi University of Technology, 1-1 Hibarigaoka, Tempaku-cho, Toyohashi 441-8580, Japan

Department of Physics, University of East Yangon, Thanlyin 11292, Yangon Division, Myanmar

mayzintoe84@gmail.com matsuda@ee.tut.ac.jp, sypung@usm.my

Keywords: Dip coating, ZnO layers, annealing,

Abstract

Zinc sol deposited via dip coating on Fluorine-doped Tin Oxide (FTO) coated glasses were annealed at in normal ambient to form ZnO layers. The effect of annealing durations, i.e. 30, 60, 90, and 120 min on their surface morphology, crystallinity, optical, electrical and Dye-Sensitized Solar Cells (DSSCs) performance were studied. The XRD analyses indicated the formation of wurtzite ZnO after 60 min of annealing. It is noted that the ZnO layers annealed at showed good crystal quality attributed to its sharp, narrow and strong diffraction peaks. Generally, ZnO layers with uniform thickness have been deposited on the FTO coated glasses. The thickness of ZnO layers decreased from , and when the annealing duration increased from 30 to 120 min due to removal of hydrocarbons from the zinc sol. The O at. % increased with annealing duration, indicating that more oxygen reacted with zinc to form ZnO . The ZnO thin film annealed at 60 min had relatively low sheet resistance ( ) with optical bandgap of 3.04 eV . This suggests that ZnO layers annealed at 60 min have the largest amount of oxygen vacancies that contributed electrons for charges transportation in the layers. Besides, the Room Temperature Photoluminescence (RTPL) analyses showed that the ZnO thin film annealed for 60 min showed ratio , suggesting better crystal quality compared to shorter annealing duration.

Introduction

The original version of this paper is available on https://www.scientific.net/EI.9.1.pdf

Transparent conductive coatings (TCCs) based on semiconductor oxides in particular have a wide range of applications such as in optical devices, photovoltaic cells and displays. Zinc oxide ( ZnO ) is a semiconductor oxide nanomaterial that crystallizes in wurtzite structure and have direct bandgap of 3.37 eV with an exciton binding energy of 60 meV at room temperature. Due to these unique properties, ZnO is a potential candidate for piezoelectric transducers [1], optical waveguides [2], acousto-optic media [3], conductive gas sensors [4] and TCCs[5].

Development of a cost- and time-effective deposition technique to produce ZnO layer with controlled uniform thickness and electrical property is needed for the above applications. Many deposition techniques have been established for ZnO layer deposition, for instances, sol-gel [6], hydrothermal [7], atomic layer deposition [8] and chemical vapor deposition [9]. It is noted that these deposition techniques affect the structural, optical and electrical properties of ZnO layers due to variation in compositions [10], crystalline phases [11] and microstructures [10], or inhomogeneous multilayer [12] or composite structure [13].

Dip-coating technique has been chosen in this work because of its simple and low cost process. It is suitable for mass production and easy to up-scale for deposition on larger size of substrates. Nevertheless, this process suffers from uneven thickness, which could affect the electrical conductivity of the ZnO layers. In addition, the reduction of deposition thickness after annealing is not explained in literature. A ZnO seed layer was pre-coated on the surface of FTO glass substrates in order to facilitate the deposition of ZnO layers in subsequent dip-coating process. This improved
the uniformity of ZnO thickness and achieved full deposition (coverage) of ZnO layer on the FTO glass substrates. The purposes of this work are to study the effects of annealing duration on the structural, optical and electrical properties of ZnO layers. The mechanism of reduction of ZnO layers' thickness after annealing also discussed based on the findings in this work.

Experimental Setup

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The pre-cut FTO coated glasses ( , sheet resistance of ) were ultrasonically cleaned using detergent (Decon 90, UK) for 15 min and then rinsed with 2-propanol, ethanol and DI water. The substrates were dried in oven for 1 hr at . Next, zinc sol was deposited on the glass substrates by dip-coating. This was done by dipping vertically the glass substrates into the precursor solution. The solution was a mixture of 0.125 M zinc acetate dihydrate and 0.125 M diethanolamine. The dipping process was carried out using a dip-coating controller (Aiden). The dipping parameters were kept consistent, i.e. down-speed was maintained at with a dwell time of 10 s and a withdrawing speed of . Subsequently, the substrates were dried at for 15 min in an oven. The dip-coating was repeated 3 cycles to achieve complete coverage and uniform thickness of zinc sol on the glass substrates. The substrates were annealed in normal ambient at for 30,60 , 90 and 120 min .

The crystal phase of ZnO layers characterized by X-ray diffractometry (XRD, Rigaku RINT 2500) with a radiation ( ). The microstructures of ZnO layers were observed by field emission scanning electron microscope (FE-SEM, HITACHI, S-4800) using accelerating voltage of 40 kV . The average film thickness was measured using Image J software. The optical properties of ZnO layers were analysed using an ultraviolet-visible near infrared spectrophotometer (V-670, JASCO Corporation, scanning range: ), a Raman spectroscope (NRS-3100, JASCO Corporation) and room temperature photoluminescence (RTPL) spectroscope (KIMMON KOHA , excitation wavelength: 325 nm ).

Results and Discussion

The original version of this paper is available on https://www.scientific.net/EI.9.1.pdf

Structural properties of ZnO layers

The original version of this paper is available on https://www.scientific.net/EI.9.1.pdf

The ZnO layers was annealed at but with different durations, i.e. varied from 0 (asdeposited), 30, 60, 90 and 120 min. Fig 1 shows the XRD pattern of ZnO layers annealed at different durations. The Brag diffractions at 26.49, 33.62, 37.68, 51.49, 54.46, 61.49, 64.15, 65.51, 70.77 and correspond to (110), (011), (020), (121), (220), (130), (112), (031), (230) and (231) of tin oxide with crystal structure of FTO JCPDS (98-006-3707). No diffraction peaks related to ZnO were measured for as-deposited thin film and thin forms annealed for 30 min . Nevertheless, diffraction peaks associated with ZnO were found at a longer annealing duration, i.e. . The diffraction peaks at 31.72, 34.37, 36.22, 56.29 and correspond to (100), (002), (101), (110) and (103) planes of hexagonal wurtzite ZnO (JCPDS-96-100-0063) with lattice constants of and .

Fig. 1. XRD pattern of ZnO layers annealed at for different durations.

Fig. 1. XRD pattern of ZnO layers annealed at for different durations.

Morphological properties of ZnO layers

The original version of this paper is available on https://www.scientific.net/EI.9.1.pdf

Fig. 2 (a) shows the morphology of bare FTO. The FTO thin film composed of large grains with uneven surface. The large grains of FTO could be still observed when a layer of zinc sol was coated on the surface of FTO glass substrate in Fig. 2 (b). The thin film layers annealed at 30 and 60 min show homogeneous closely packed and tiny particles ( ) in Fig. 2 (c) and (d). No pinhole and crack could be found on the surface of layers. A longer annealing duration, i.e. 90 and 120 min , producing larger particles as seen in Fig. 2 (e) and (f). This is an indication of Ostwald ripening effect, where tiny particles dissolved and re-deposited to form large particles [14]. Nevertheless, these layers have porous structure with loosely bound particles on the substrate surface. In addition, cracks were found on these layers as highlighted in Fig. 2 (e) and (f).

Fig. 2. FESEM images of (a) bare FTO, and ZnO layers annealed at for (b) 0 (as-deposited), (c) 30 , (d) 60 , (e) 90 and (f) 120 min

Fig. 2. FESEM images of (a) bare FTO, and ZnO layers annealed at for (b) 0 (as-deposited), (c) 30 , (d) 60 , (e) 90 and (f) 120 min

Fig 3 (a)-(e) shows the cross-sectional view of ZnO layers thickness annealed at different durations. The thickness of as-deposited zinc acetate thin film is . By extending the annealing duration, the thickness of layers decreased from and for and 120 min., respectively as plotted in Fig 3 (f). The reduction of thickness was due to oxidation of zinc acetate into ZnO and burning off of hydrocarbons from the ZnO layers as described in Eq. (1), releasing by products such water and carbon dioxide. A longer annealing time allowed more complete oxidation of zinc acetate. Long annealing duration, i.e. 90 and 120 min , were not favoured as cracks, loosely bound particles and porous structures were observed on the surface of ZnO layers.

Fig. 3. FESEM cross-sectional images of ZnO layers at annealing temperature for (a) 0 (asdeposited), (b) 30, (c) 60, (d) 90, (e) 120 min and (f) thin film thickness versus annealing durations.

Fig. 3. FESEM cross-sectional images of ZnO layers at annealing temperature for (a) 0 (asdeposited), (b) 30, (c) 60, (d) 90, (e) 120 min and (f) thin film thickness versus annealing durations.

EDX measurement was performed to determine the atomic ratio of Zn to O . The atomic ratio of Zn and O is shown in Fig 4. The O at. % increased with annealing duration, indicating that more oxygen reacted with zinc to form ZnO. Nevertheless, this could affect the sheet resistance of ZnO layers as it is known that electrons are usually contributed from oxygen vacancies [15, 16]. The result shows that ZnO thin film annealed at 60 min has higher Zn atoms as compared to O atoms, indicating that it has the largest oxygen vacancies in the film. The presence of ZnO was not detected by XRD in Fig. 1 for as-deposited film and film annealed for 30 min . Thus, ZnO formed after annealing of more than 60 min .

Fig. 4. EDX analysis of ZnO layers annealed at for different durations.

Fig. 4. EDX analysis of ZnO layers annealed at for different durations.

Optical properties of ZnO layers

The original version of this paper is available on https://www.scientific.net/EI.9.1.pdf

The effect of annealing duration on the sheet resistance of ZnO layers is displayed in Fig. 5. The as-deposited thin film (zinc acetate) recorded sheet resistance of . The sheet resistance decreased with increasing annealing duration, achieving at 60 min. Formation of ZnO layers which contained many oxygen vacancies was believed the cause of this observation. It is known that charge carriers transportation in ZnO layers is via electrons (n-type, majority charge carriers). These electrons were mainly contributed from the oxygen vacancies in ZnO layers [17].

Nevertheless, the sheet resistances of ZnO layers increased with pro-long annealing duration. It was measured after annealed for 120 min . The increase of O at. % in Fig. 4 (EDX) with pro-long annealing indirectly indicates the reduction of oxygen vacancies in ZnO layers. Since oxygen vacancies were the main source of electrons for charges transportation, the reduction of oxygen vacancies in ZnO layers would increase the sheet resistance after pro-long annealing. In addition, the presence of cracks, loosely bounded particles and porous structure in ZnO layers (Fig 2. (e) and (f)) could also increase the resistance for the movement of charge carriers in the ZnO layers.

Fig. 5. Sheet resistance of ZnO layers annealed at for different durations.

Fig. 5. Sheet resistance of ZnO layers annealed at for different durations.

Fig. 6 (a) shows the optical transmission spectra of ZnO layers recorded in the wavelength region of for different annealing durations. In general, the ZnO layers are highly transparent with an average transmission of in the visible range. Fig. 6 (b) shows the absorption of layers. The layers have absorption edges at which correspond to optical bandgap of ZnO. Fig. 6 (c) shows the Tauc plot of layers annealed at different duration. It was found that the optical bandgap increased with annealing duration, i.e. from 2.71 (as-deposited) to 3.13 eV as shown in Fig. 6 (d). The optical bandgap was closed to the literature report value, i.e. 3.37 eV [18]. Pro-long annealing duration allowed more oxygen to react with zinc in order to form ZnO .

Fig. 6. (a) Transmittance, (b) absorbance,(c) Tauc plot and (d) optical bandgap of ZnO layers annealed at for different durations

Fig. 6. (a) Transmittance, (b) absorbance,(c) Tauc plot and (d) optical bandgap of ZnO layers annealed at for different durations

Fig. 7 shows the Raman spectra of layers annealed at different durations. The Raman shifts at 458 and associated with (High) and (LO) modes are observed. The (High) mode is related to vibration of oxygen atoms in ZnO . Thus, presence of (High) was an indication of ZnO formation. The presence of indicates that the layers contained crystal defects such as oxygen vacancies [19]. This observation is agreed well with the finding in the EDX analysis that the layers were lacked of oxygen (Fig. 4).

Fig. 7. Raman spectra of ZnO layers annealed at for different durations

Fig. 7. Raman spectra of ZnO layers annealed at for different durations

The room temperature PL spectrum of ZnO layers with various annealing durations is shown in Fig 8. A sharp UV emission (NBE) ( 385 nm ) accompanied with a broad visible light emission (defect related) in green-orange band ( ) are observed in all layers as displayed in Fig 8 (a). The effect of annealing temperature on the maximum peaks of UV and visible light emission were negligible as it was random as shown in Fig 8 (b) and (c). Nevertheless, the ratio increased with increasing duration as shown in Fig 8 (d), although a slight drop was observed at 120 min. The result suggests that less crystal defects present in ZnO layers at pro-long annealing duration. The crystal quality of layers was improved as more oxygen were allowed to react with zinc acetate for the formation of ZnO.

Fig. 8. (a) Room temperature photoluminescence, (b) shift of maximum peak in UV regime (NBE), (c) shift of maximum peak in visible light regime (defect-related emission), (d) Iuv/Ivis ratio of ZnO layers annealed at different durations

Fig. 8. (a) Room temperature photoluminescence, (b) shift of maximum peak in UV regime (NBE), (c) shift of maximum peak in visible light regime (defect-related emission), (d) Iuv/Ivis ratio of ZnO layers annealed at different durations

Table 1 summarizes the findings of ZnO layers annealed at with different durations. This table shows that the length of annealed duration time affected the crystal growth. A longer annealing time provided more reaction time and thermal energy that were required for crystal growth and recrystallization. After maintaining the annealing duration over 30 min , dense and hexagonal crystal grains were obtained. The appropriate annealing duration to produce ZnO thin film was 60 min. At this annealing duration, no glass deformation and thin film delamination were observed. Besides, the analyses indicate that the thin film was ZnO with good thickness uniformity and crystal quality ( ratio ). The ZnO thin film had relatively low sheet resistance ( ) with optical bandgap of 3.04 eV .

Table 1. Structural and optical properties of ZnO layers annealed at different annealing durations

No. | Observation | As-deposited | 30 min | 60 min | 90 min | 120 min
1 | Substrate deformation | No | No | No | Yes | Yes
2 | Detection of ZnO (XRD) | No | No | Yes | Yes | Yes
3 | Thickness uniformity (FESEM) | Yes | Yes | Yes | Yes | Yes
4 | Thin film delamination (FESEM) | No | No | No | No | No
5 | Zn : O atomic ratio (EDX) | 76:24 | 73:27 | 69:31 | 53:47 | 24:76
6 | Sheet resistance (Ω/□) | 11.4 | 10.1 | 9.6 | 10.4 | 11.1
7 | Optical bandgap (eV) (UV-Vis) | 2.71 | 3.02 | 3.06 | 3.09 | 3.13
8 | Raman shift: E₂ (High) mode | No | No | Yes | Yes | Yes
9 | Crystal quality (RTPL: Iuv/Ivis ratio) | 0.67 | 0.86 | 0.89 | 1.03 | 0.81

Fig. 9 illustrates the annealing effect on the structural, optical and electrical properties of ZnO
layers based on the observation from FESEM images, XRD analyses and sheet resistance
measurement. In short annealing duration ( 30 min ), water vaporization and oxidation of hydrocarbons happened on the surface of thin film. Only a small portion of zinc sol near the sub-surface could be decomposed and oxidized into ZnO . The presence of this ZnO was too little to be detected by XRD and Raman spectroscopy. Most of the deposited thin film still remained as zinc sol. As a result, the thin film had the highest sheet resistance ( ), narrow bandgap ( 2.71 eV ) and poor ratio (0.67) in RTPL measurement.

By prolonging the annealing duration to 60 min , more water and hydrocarbons were removed from thin film. More zinc sol was oxidized into ZnO as signals associated with ZnO were detected by both XRD and Raman spectroscopy. This caused shrinkage of thin film thickness from to . The thin film had the lowest sheet resistance ( ), wide bandgap ( 3.06 eV ) and better ratio (0.89). Nevertheless, it is believed that there were still some zinc sol remained particularly at the parts that close to FTO substrate. The oxygen from ambient needed more time to diffuse into the layers and to oxidize the zinc sol.

Further annealed the thin film to 120 min resulted in the formation of pores, cracks, shrinkage and delamination of thin film due to fully decomposition and oxidation of zinc sol into ZnO . The presence of these crystal defects in the thin film increased the sheet resistance to .

Fig. 9. Effect of annealing duration on the structural of ZnO layers that annealed at .

Fig. 9. Effect of annealing duration on the structural of ZnO layers that annealed at .

Conclusions

The original version of this paper is available on https://www.scientific.net/EI.9.1.pdf

ZnO layers were deposited on FTO glass substrates using dip coating method. Process optimization was performed by varying annealing durations (As-deposited, 30, 60, 90 and 120 min ) at the annealing temperature . The annealing duration determined the crystal growth and completeness of oxidation of zinc sol to form ZnO . Short annealing duration (< 30 min ) was insufficient to oxidize the zinc sol into ZnO . ZnO was detected by XRD analysis when the layers
were annealed more than 60 min. Nevertheless, long annealing duration ( 120 min ) caused thin film peeling or cracks and even significant deformation on glass substrates. The study showed that ZnO thin film annealed at 60 min has the lowest sheet resistance ( ) with optical bandgap of 3.04 eV and good ratio .

Acknowledgement

The original version of this paper is available on https://www.scientific.net/EI.9.1.pdf

The authors gratefully acknowledge the financial support of Ministry of Higher Education, Malaysia for providing the research funding under Fundamental Research Grant Scheme (FRGS) (FRGS/1/2020/TK0/USM/02/27) to conduct this project and the support from the USM Fellowship.

Research Data Policy and Data Availability Statements

The original version of this paper is available on https://www.scientific.net/EI.9.1.pdf

The datasets generated during and/or analysed during the current study are available from the corresponding author on reasonable request.

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The original version of this paper is available on https://www.scientific.net/EI.9.1.pdf

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The original version of this eBook is available on https://www.scientific.net/book/engineering-innovations-vol-9/978-3-0364-1504-8

Engineering Innovations, ISSN: 2813-1002, Vol. 9, pp 15-21

doi: 10.4028/p-ShG23P

© 2024 The Author(s). Published by Trans Tech Publications Ltd, Switzerland.

Submitted:
2023-06-26

Accepted:
2023-07-17

Online:
2024-02-12

Use of Polyacrylonitrile as Anodic Artificial Solid Electrolyte Interphase for Aqueous-Based Zinc-Ion Batteries

The original version of this paper is available on https://www.scientific.net/EI.9.15.pdf

Nutchaya Muangplod , Anongnat Somwangthanaroj and Soorathep Kheawhom

¹Polymer Engineering Laboratory, Department of Chemical Engineering, Faculty of Engineering, Chulalongkorn University, Bangkok 10330, Thailand

Research Unit of Advanced Materials for Energy Storage, Faculty of Engineering, Chulalongkorn University, Bangkok 10330, Thailand

student.chula.ac.th, anongnat.s@chula.ac.th, soorathep.k@chula.ac.th

Keywords: Rechargeable aqueous zinc-ion batteries; Zinc anode; Polyacrylonitrile.

Abstract

Rechargeable aqueous zinc-ion batteries (ZIBs) have attracted attention for energy storage systems because of their high specific capacity, low cost, and safety. However, practical application of the zinc anode in mild acidic electrolytes is limited by several issues such as dendrite formation, corrosion, hydrogen evolution reaction, passivation and relatively low cycling performance. Coating the zinc anode with graphite (GP) can partially solve these issues and improves the cycling performance of ZIB. However, after long-term charge/discharge cycles, zinc tends to migrate and redeposit over the surface of GP owing to the electronic conductivity of GP particles. Thus, after long-term cycling, the issues mentioned are back. Fabrication of artificial solid electrolyte interphase (ASEI) on the surface of the zinc anode shows high potential for solving these issues. In this work, polyacrylonitrile (PAN) with zinc trifluoromethanesulfonate (PANZ) as ASEI was coated on the GP layer onto the zinc anode (PANZ@GP@Zn), and compared with the anode having GP coated layers and pristine zinc anode. The coating layer was prepared by the doctor blading method. The result showed that the PANZ@GP@Zn anode can reduce zinc deposition over the anode surface when compared with the GP@Zn anode, leading to the high cycling stability of ZIBs and extending the battery's life.

Introduction

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The demand for renewable energy has risen rapidly due to fossil fuels over-consumption and environmental pollution and global warming issues. However, renewable energy is difficult to store, transport and its fluctuating nature. Therefore, an energy storage system (ESS) has been developed to provide a more versatile and stable power supply for personal, household and industrial applications [1].

The most well-studied energy storage system and widely used in the energy market is lithiumion batteries (LIBs), which can provide high energy density, and long cycle lifetime [2]. Nonetheless, commercial LIBs are still suffer from high cost due to the limited lithium resource and safety issues, also hinder their development for large-scale energy storage applications. Considering these limitations of LIBs, it is necessary to search for new battery technology based on high safety, low cost, and long cycle life [3].

Rechargeable aqueous zinc-ion batteries (ZIBs) have been considered as the promising alternative energy storage system due to their high theoretical capacity ( ), high natural abundance, low cost, environmental friendliness, and high safety [4]. However, the practical application of the zinc anode in mild acidic electrolytes is limited by several issues such as dendrite formation, corrosion, hydrogen evolution, passivation on the zinc surface, which reduces coulombic efficiency and cycling performance of ZIBs [1,4].

One of various carbon materials that is a good alternative for using in zinc anodes is graphite (GP) due to its homogeneous electric field distribution, abundant active sites, and satisfying
durability, leading to the enhancement on the cycling performance of ZIBs [5, 6, 10]. Hence, coating the zinc anode with graphite can partially solve these issues. However, after long-term charge/discharge cycles, zinc tends to migrate and redeposit over the surface of the carbon layer owing to a good electronic conductivity of carbon particles [3]. Thus, after long-term cycling, the mentioned issues are back.

Polyacrylonitrile (PAN) is a solid polymer electrolyte that is attractive for use in ZIBs due to its low cost, chemical stability, excellent thermal stability, high tensile strength and tensile modulus. The polar nitrile group (-CN) can provide coordination sites to bridge ions. Nevertheless, polyacrylonitrile has partially hydrophobicity (ionic conductivity ), so it is improved by adding zinc trifluoromethanesulfonate or to this polymer to increase its hydrophilicity and higher ionic conductivity [7]. Also, The anions of can react with ions [8]. Hence, Polyacrylonitrile with zinc trifluoromethanesulfonate are used as artificial solid electrolyte interphase (ASEI) on the surface of the zinc anode that can regulate zinc ion distribution and uniform nucleation sites for zinc deposition on the anode surface [9]. Thus, ASEI shows high potential for solving the tendency that zinc tends to migrate and redeposit over the surface of carbon.

In this study, polyacrylonitrile (PAN) with zinc trifluoromethanesulfonate (PANZ) as ASEI was coated on the graphite (GP) layer onto the zinc anode (PANZ@GP@Zn), and the results were compared to the anode having graphite coated layers and bare zinc anode in rechargeable aqueous zinc-ion batteries.

Experimental Section

The original version of this paper is available on https://www.scientific.net/EI.9.15.pdf

Materials. Graphite (GP) powder, , polyacrylonitrile (PAN) (MW. 150,000 g/mol), zinc trifluoromethanesulfonate was purchased from Sigma-Aldrich, n,n-dimethyl formamide (AR/ACS grade) (DMF) was purchased from Loba Chemie, n-methylpyrrolidone (AR grade) (NMP) was purchased from Quality reagent chemical, poly(vinylidene fluoride) (Solef ® PVDF) (MW. ) was purchased from Solvay, zinc sulfate 7 -hydrate (AR grade, MW ) was purchased from Kemaus, zinc foil (thickness: 0.05 mm ), graphite foil (thickness: 0.05 mm ), glass microfiber paper ( , Whatman) and blank coin cell CR2025 as well as other materials were used as received.

Preparation of negative electrodes. The graphite was mixed with polyvinylidene fluoride (PVDF) in n-methylpyrrolidone (NMP) solution with the weight ratio of carbon: PVDF as a binder which was 80:20, that was prepared under stirring at room temperature until it was homogeneous. It was then pressed onto a Zn foil (thickness, ) by the doctor blading method, and dried at for overnight in vacuum to evaporate the solvent. The PANZ layer preparation was to dissolve 1.0 g polyacrylonitrile (PAN) into 9.0 g dimethylformamide (DMF) under stirring ( 800 rpm ) at until the polymer completely dissolved, then 1.0 g zinc trifluoromethanesulfonate was dissolved in the solution. It was then pressed onto GP@Zn which has been prepared before by the doctor blading method, and dried on the doctor blading machine at for 3 h to evaporate the solvent. Finally, anode sheet was obtained and cut into a circular shape with 15 mm in diameter. The thickness of the polymer coating layer was .

Preparation of positive electrodes. The was chosen as a cathode for the battery. The was made by dissolving 1.98 g of in 60 mL of deionized (DI) water. Then, was dissolved in 20 mL of DI water and dropped into the solution, which had been stirred continuously for 30 minutes. The solution was transferred to a 100 mL Teflon autoclave and heated at in an oil bath for 24 hours. The product was collected and cleaned with DI water. It was then dried at for 12 hr . After the was obtained, it was then mixed with other components as follows. The weight ratio of :super P:PVDF as a binder was 80:10:10 under stirring until it was homogeneous. It was then pressed onto a graphite (thickness, 50
by the doctor blading method, and dried at overnight in vacuum to evaporate the solvent. Finally, cathode sheet was obtained and cut into a circular shape with 15 mm in diameter. The batteries were fabricated as a CR2025 coin cell.

Material characterization. The morphology of the anode and separator surface images both initial and after cycling were obtained using the field emission scanning electron microscope (FESEM).

Electrochemical measurement. Electrochemical impedance spectroscopy (EIS) and Tafel curves were conducted via the potentiometer on three electrodes including bare and coated ones (bare Zn, GP@Zn and PANZ@GP@Zn) which were the working electrode, zinc foil was counter electrode and was reference electrode. The other electrochemical performances were investigated with CR2025 coin cells consisting of a working electrode, a counter electrode, and glass microfiber wetted with electrolyte for symmetrical Zn cells and electrolyte for full cells. Electrochemical impedance spectroscopy (EIS) measurements were carried out with VersaSTAT tool over the frequency range between and 0.1 Hz with an AC voltage of 10 mV and indicated the electronic and ionic conductivities. The Tafel curves of bare and PANZ@GP@Zn measured in at a scan rate of . This test was evaluated the corrosion and hydrogen evolution reaction on the anode surface. The galvanostatic charge/discharge cycling was performed on battery-testing system. The symmetrical cell with the bare Zn, GP@Zn and PANZ@GP@Zn was to evaluate the striping/plating performance of batteries. The long-term cycling performance and cycling stability of the zinc anodes were measured at a current density of with fixed capacity of . The coulombic efficiency (CE) was the percentage of discharging capacity compared with the charging capacity to evaluate the battery's reversibility. The CE of half cells were measured at a current density of with fixed capacity of . The rate capability of the full batteries were carried out at current densities of , and , respectively. The current density and specific capacity values of the electrodes were normalized to the mass of .

Results and Discussion

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The cross-sectional field emission scanning electron microscopy (FE-SEM) images of PANZ@GP@Zn as shown in Figure 1A was used to inspect the morphologies of the anode surface and thickness of coating layer before charging/discharging process, in which it was found that thickness of the PANZ layer and the graphite layer were and approximately , respectively. To test the impedance and ionic conductivity of zinc electrodes with bare Zn , graphite coated zinc ( ) and zinc was coated with the PANZ and graphite (PANZ@GP@Zn) in concentrated aqueous electrolyte of . As shown in Figure 1B The Nyquist curves of impedance spectra of the different anodes before cycling presented the PANZ interfacial coating layer (PANZ@GP@Zn) reduced the impedance of the zinc anode more than the graphite layer (GP@Zn) and without coating layer (bare Zn). The result showed the PANZ@GP@Zn had the highest ionic conductivity, which implied that the fast transport through the PANZ layer. The anticorrosion capability of coating layer on anode and the effect of the PANZ coated graphite and graphite coated on the zinc corrosion were analyzed by Tafel curves in an electrolyte of as shown in Figure 1C. Compared to the bare Zn, the corrosion potential of PANZ@GP@Zn and GP@Zn increase from -0.9613 V to -0.9465 V and from -0.9613 V to -0.9510 V , respectively. The result showed more positive corrosion potential that indicates less tendency of corrosion reactions and hydrogen evolution reaction [7, 11]. Moreover, the PANZ layer also reduced the corrosion current. Thus, the PANZ@GP@Zn has a lower corrosion rate. When compared GP@Zn, the PANZ layer had the more positive corrosion potential, which indicated that the PANZ layer tends to be more corrosion resistant than GP@Zn.

Fig. 1. Morphology analysis of PANZ@GP@Zn electrodes, EISs and Tafel curves of different zinc anodes. A) Cross-section view FE-SEM image of PAN@GP@Zn electrode before charging/discharging process. B) Electrochemical impedance spectra (EIS) of symmetric cells with bare Zn, GP@Zn and PANZ@GP@Zn anodes before cycling test. C) Tafel curves of bare Zn, GP@Zn and PANZ@GP@Zn in electrolyte.

Fig. 1. Morphology analysis of PANZ@GP@Zn electrodes, EISs and Tafel curves of different zinc anodes. A) Cross-section view FE-SEM image of PAN@GP@Zn electrode before charging/discharging process. B) Electrochemical impedance spectra (EIS) of symmetric cells with bare Zn, GP@Zn and PANZ@GP@Zn anodes before cycling test. C) Tafel curves of bare Zn, GP@Zn and PANZ@GP@Zn in electrolyte.

The morphologies of the bare Zn, GP@Zn and PANZ@GP@Zn electrodes before cycling and after 100 cycles was examined by FE-SEM as shown in Figure 2. The FE-SEM images displayed the morphologies of the electrodes before cycling. The morphology of bare Zn in Figure 2A had quite smooth surface but some area had rough surface. The morphology of graphite coated Zn (GP@Zn) in Figure 2B showed the rough surface with considerable voids. The morphology of the PANZ layer and graphite coated Zn in Figure 2C showed micropores over the surface. However, after 100 charge/discharge cycles, the bare Zn cell was covered all over by corrosion pits, Zn dendrites as shown in Figure 2D. The formation of dendrites is also problem of Zn anode because inactive dendrite can block the transfer of ions and slow the ion diffusion process, while the GP@Zn in Figure 2E cell showed zinc deposit over the surface of graphite layer caused by zinc migrated from interface between the zinc anode and the graphite layer onto the graphite layer due to good electronic conductivity of graphite particles. In contrast, the PANZ@GP@Zn cell as shown in Figure 2F found slightly zinc on the surface of polymer layer caused by zinc deposited between the graphite surface and the PANZ layer. Compared to the carbon layer, the PANZ layer can reduce zinc deposition over the anode surface.

Fig. 2. Morphologies of electrodes and separators disassembled from symmetrical cell. Top view FESEM of images of Zn electrode with bare Zn, GP@Zn and PANZ@GP@Zn (A, B, C) before the cycling test, (D, E, F) after 100 cycles. Top view FE-SEM of images of glass microfiber separators with G-I) GP@Zn and J-L) PANZ@GP@Zn after 100 cycles at a current density of with .

Fig. 2. Morphologies of electrodes and separators disassembled from symmetrical cell. Top view FESEM of images of Zn electrode with bare Zn, GP@Zn and PANZ@GP@Zn (A, B, C) before the cycling test, (D, E, F) after 100 cycles. Top view FE-SEM of images of glass microfiber separators with G-I) GP@Zn and J-L) PANZ@GP@Zn after 100 cycles at a current density of with .

The morphologies of glass microfiber separator disassembled from the symmetrical cell with GP@Zn electrode, PANZ@GP@Zn electrode after 100 cycles at a current density of with . As shown in Figure 2J, 2K and 2L, the glass microfiber separator of PANZ@GP@Zn electrode showed glass microfiber without dendrite. The separator of GP@Zn electrode as shown in Figure 2G and 2I showed flake-shaped dendrites spread on the separator surface and the separator pierced by dendrites as shown in Figure 2 H , leading to the internal short circuit in the cell.

To evaluate the stability of symmetrical Zn cells with bare Zn, GP@Zn and PANZ@GP@Zn were assembled with and inspected with the galvanostatic charge/discharge cycling test. After 25 cycles ( 50 hours) at a current density of with a capacity of as shown in Figure 3A, the cycling curve of bare Zn cell showed serious fluctuation and short circuit at 35 cycles ( 70 hours), which was inhomogeneous current distribution caused by the surface morphologies of bare Zn change during the charging/discharging processes of ZIBs due to dendrites, corrosion pits, hydrogen gas bubble found on the surface of bare Zn (Figure 2D) [5, 10]. On the other hand, the cycling curve of graphite coated Zn cell (GP@Zn) demonstrated more stable cycling than bare Zn
but the GP@Zn had reduced polarization voltage from 0.0390 V to 0.0186 V , which implied that the GP@Zn had migrated of Zn ions from the interface surface between Zn foil and the graphite layer to redeposition over the surface of graphite owing to good electronic conductivity of graphite particles [3]. Thus, the cycling curve of GP@Zn exhibited short circuit at 85 cycles ( 170 hours) because glass microfiber separator pierced by dendrites. In contrast, the PANZ@GP@Zn showed very stable curves during 250 cycles ( 500 hours) caused by the PANZ layer (Polyacrylonitrile with zinc trifluoromethanesulfonate) as ASEI which can regulate zinc ion distribution and uniform nucleation sites for zinc deposition on the anode surface, leading to suppressing side reactions and high cycling stability of ZIBs [7]. Therefore, the PANZ@GP@Zn cell has the most stability cycling and long-term cycling than bare Zn and GP@Zn cell.

Fig. 3. Long-term cycling stability of symmetrical cells, the coulombic efficiency (CE) and Rate capability. A) The cycling performance of the symmetrical cells with bare and PANZ@GP@Zn at a current density of with . B) The coulombic efficiency (CE) of Zn plating/stripping in the Cu-Zn, GP@Cu-GP@Zn and PANZ@GP@Cu-PANZ@GP@Zn half cells. C) Rate capability of full batteries from and based on the mass of .

Fig. 3. Long-term cycling stability of symmetrical cells, the coulombic efficiency (CE) and Rate capability. A) The cycling performance of the symmetrical cells with bare and PANZ@GP@Zn at a current density of with . B) The coulombic efficiency (CE) of Zn plating/stripping in the Cu-Zn, GP@Cu-GP@Zn and PANZ@GP@Cu-PANZ@GP@Zn half cells. C) Rate capability of full batteries from and based on the mass of .

To investigate the effect of the PANZ coating layer and graphite layer on the coulombic efficiency (CE) of the reversibility of the process. During each cycling, Zn was dissolved from the Zn metal as cathode and deposits onto the Cu as anode. The CE of half-cell with PANZ@GP@Cu|PANZ@GP@Zn was evaluated and compared with bare Cu|bare Zn and GP@Cu|GP@Zn cells. The test was carried out by plating zinc (fixed areal capacity: ) onto the and PANZ@GP@Cu substrate. As displayed in Figure 3B, fluctuant voltage signals during Zn plating/stripping were observed with the bare Cu and the GP@Cu electrode because of side reactions. On the other hand, the PANZ@GP@Cu cell presented a very stable coulombic efficiency (CE) over 100 cycles ( 200 h ), maintaining an average CE of from cycle 10 ( ) to .

Full prototype cells were assembled to prove the practical application of our electrode. One of the most commonly used cathodes for aqueous ZIBs was delta-MnO2 , the was investigated to further evaluate the impact of the PANZ coating layer and graphite layer on the electrochemical performance of full batteries consisting of bare and PANZ@GP@Zn cells. The cells were charged/discharged in electrolyte, and additive was used to suppress the dissolution of from the cathode [11, 12]. The rate capability of the bare and batteries were also tested at various current densities ranging from and . As shown in Figure 3C, the rate capability of the PANZ@GP@Zn was better than that of and , which implies that can reduce the fading of capacity than other anodes.

Summary

The original version of this paper is available on https://www.scientific.net/EI.9.15.pdf

In this work, using polyacrylonitrile with zinc trifluoromethanesulfonate as ASEI on the graphite (GP) layer onto the zinc anode (PANZ ). Compare with the anode having graphite coated layers (GP@Zn) and bare zinc anode in rechargeable aqueous zinc-ion batteries (ZIBs). The PANZ@GP@Zn can increase ionic conductivity and less tendency of corrosion reactions and hydrogen evolution reaction. Moreover, the PANZ layer can reduce zinc deposition over the anode surface when compared with the carbon layer, leading to suppressing side reactions. Thus, the PANZ@GP@Zn has high cycling stability, long-term cycling performance of ZIBs and extending the battery's life. To identify the practical application, the PANZ@GP@Zn is suitable anode that can reduce the fading of capacity.

References

The original version of this paper is available on https://www.scientific.net/EI.9.15.pdf

W. Du, E.H. Ang, Y. Yang, Y. Zhang, M. Ye, C.C. Li, Challenges in the material and structural design of zinc anode towards high-performance aqueous zinc-ion batteries, Energy & Environmental Science. 13(10) (2020) 3330-3360.

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H. Tao, X. Tong, S. Zhang, X. Zhang, X. Liu, Effect of adding various carbon additives to porous zinc anode in rechargeable hybrid aqueous battery, Journal of Alloys and Compounds. 658 (2016) 119-124.

P. Chen, X. Yuan, Y. Xia, Y. Zhang, L. Fu, L. Liu, N. Yu, Q. Huang, B. Wang, X. Hu, Y. Wu, T. van Ree, An Artificial Polyacrylonitrile Coating Layer Confining Zinc Dendrite Growth for Highly Reversible Aqueous Zinc-Based Batteries, Advanced Science. 8(11) (2021) 2100309.

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Z. Zhao, J. Zhao, Z. Hu, J. Li, J. Li, Y. Zhang, C. Wang, G. Cui, Long-life and deeply rechargeable aqueous Zn anodes enabled by a multifunctional brightener-inspired interphase, Energy & Environmental Science. 12(6) (2019) 1938-1949.

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This ePub file was created using machine-generated methods and automated software to convert the source text into an ePub format and may contain formatting inconsistencies from the original version. Formatting may vary depending on the device used.

The original version of this eBook is available on https://www.scientific.net/book/engineering-innovations-vol-9/978-3-0364-1504-8

Engineering Innovations, ISSN: 2813-1002, Vol. 9, pp 23-30

doi: 10.4028/p-1BMxJg

© 2024 The Author(s). Published by Trans Tech Publications Ltd, Switzerland.

Submitted:
2023-06-26

Revised:
2023-10-04

Accepted:
2023-10-04

Online:
2024-02-12

Cathodized Stainless Steel Mesh for Binder-Free Layer Double Hydroxides Oxygen Evolution Reaction Electrode

The original version of this paper is available on https://www.scientific.net/EI.9.23.pdf

Natthapon Sripallawit and Soorathep Kheawhom

Research Unit of Advanced Materials for Energy Storage, Chulalongkorn University, Bangkok 10330, Thailand

6370081821@student.chula.ac.th, soorathep.k@chula.ac.th

Keywords: Electrocatalyst; Oxygen evolution reaction; Cathodization

Abstract

Oxygen evolution reaction (OER) is an essential reaction commonly applied in various energy storage and conversion technologies. One of the common issues of OER lies in its low kinetic activity. Therefore, developing durable, low-cost, and high-performance OER catalysts is critical. Recently, many attempts have used stainless steel mesh (SSM) as the substrate for OER electrodes because SSM is abundant, cheap, and durable. Nickel/iron-based materials, i.e., layer double hydroxides (LDHs), are regarded as one of the most excellent OER catalysts in alkaline electrolytes, making them attractive low-cost materials for OER catalysts. However, synthesizing LDHs directly on the surface of SSM is challenging. Modifying the SSM surface through cathodization has proved to enhance the adhesion and OER activity. Moreover, the cathodization technique is facile and cost-effective. In this work, the surface of SSM is modified by cathodization treatment. Subsequently, LDHs are deposited onto the surface of treated SSM via a low-temperature one-step chemical bath deposition technique. This synthesis is a binderfree method; the resulted electrodes show excellent OER performance without the binder effects. The as-prepared electrodes have a small Tafel slope of and high durability ( 10 for 50 hours).

Introduction

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Due to the obvious rising demand for energy, the demand for technology related to energy conversion and storage is increasing [1,2]. As a result, the development of efficient, cost-effective, and sustainable renewable energy technology is important. Lithium-ion batteries are now widely employed in a variety of applications, including mobile phones, laptops, and electric vehicles, and they have almost dominated the rechargeable battery market. However, lithium-ion batteries' development and applications have been hampered by their low energy density ( ), limited lithium resources, and safety concerns [3,4].

Metal-air battery is one of the more intriguing batteries. since the reactants ( ) are not kept in the cell but retrieved from the environment, the energy density of metal-air batteries is substantially higher than that of lithium-ion batteries [5]. Metal anodes for metal-air batteries come in a variety of materials, including lithium (Li), magnesium (Mg), aluminum (Al), zinc (Zn), and iron (Fe). Zn-air batteries (ZAB) have risen to the forefront of current rechargeable battery development due to their many advantages, such as: zinc is abundant in nature, has low toxicity, is extremely stable, can be handled safely in oxygen and humid environments, is economically priced, and is safe to use with aqueous electrolytes. Furthermore, gadgets made of zinc have a high specific and volumetric energy density [3, 6, 7]. Although Li-air batteries have the highest specific energy density, they are unstable when exposed to oxygen or water, necessitating an inert atmosphere and the use of organic electrolyte systems, which adds to the manufacturing complexity and safety issues. The safety concerns arise from the explosive reactivity of lithium with air or water, as well as the flammable organic electrolyte. Another disadvantage of Li-air batteries is that they are unsuitable for commercial application due to their high cost and limited lithium resources [3,4].

However, ZABs still require improvement in the oxygen evolution reaction (OER) and oxygen reduction reaction (ORR), which occur during the charge and discharge processes [8, 9]. The problem with OER is that it has inert kinetics as it relates to the occurrence of four sequential electron transfers and the formation of an oxygen-oxygen bond [10, 11]. As a result, the use of a catalyst is required. Many studies have shown that iridium dioxide ( ) and ruthenium dioxide ( ) are highly efficient OER electrocatalysts in alkaline electrolytes, but the problem with precious metals is their low natural reserves and high cost [12]. Most catalysts are prepared in powder form, which requires a polymer binder to help the catalyst bind to a conductive substrate. The binders may deteriorate from continuous cycling and from the formation of gas bubbles during the OER reaction, resulting in catalyst detachment and dramatically decreased battery lifespan [3]. Based on the aforementioned problems, efforts were made to design a well-performed, inexpensive, and binder-free OER electrode.

Nickel/iron-based materials are regarded as one of the most excellent OER catalysts in alkaline electrolytes, making them one of the attractive low-cost materials as catalysts [13, 14]. As a result, numerous investigations have concentrated on the synthesis of nickel/iron-based electrocatalysts. Layered double hydroxides (LDHs) are great suggestions among them as high-performance catalysts because they have many advantages, such as having a large number of active sites and a large specific surface area [12]. At present, there are many research that use stainless steel mesh (SSM) as the substrate of electrodes because SSM is an easy-to-find, cheap, and durable material. There are also reports that it can increase the OER activity of SSM by improving its surface. Examples of interesting surface improvements are thermal treatment and cathodization treatment. Improving its surface through cathodization can increase OER activity, and this method is also very easy to implement [15].

In this work, we created electrodes from SSM that were surface enhanced by cathodization treatment and then coated with electrocatalysts to serve as OER electrode for ZAB with high efficiency and durability.

Experimental Section

The original version of this paper is available on https://www.scientific.net/EI.9.23.pdf

Materials. Chemicals and Materials used in this work include stainless steel (304) 20 mesh was purchased from Lee Ngiab Seng (Thailand), Nickel (II) sulfate hexahydrate ( ) was purchased from Kemaus, Iron (II) Chloride tetrahydrate was purchased from Merck, Ammonia solution was purchased from Loba Chemie Pvt. Ltd., Potassium hydroxide was purchased from Kemaus.

Preparation of cathodized SSM. The SSM substrate (with dimensions of ) was ultrasonically cleaned in ethanol for 30 minutes. After that, it was cleaned with deionized water and then dried. The cathodization of SSMs was done utilizing a three-electrode setup and repetitive potential cycling, with SSM being used as the working electrode, platinum as the counter electrode, and as the reference electrode. The cathodization method was carried out in -1.8 to vs. electrolyte for up to 5 cycles at a scan rate of [15].

Preparation of LDH on cathodized SSM. Cathodized SSM were utilized as a substrate. The precursor solutions of and were transferred to a beaker, and the pH was adjusted to 10 by adding solution dropwise under vigorous stirring while the temperature was kept at using a water bath. The cathodized SSM were submerged in the aforementioned solution for 2 hours, with the reaction bath temperature kept at . Then the LDH on cathodized SSM were washed with deionized water multiple times and dried in a hot air oven at for 1 hour [16].

Physical characterizations. The morphology and elements distribution of SSM surface was studied using field emission scanning electron microscopes (FE-SEM). The composition and
oxidation state of the synthesized LDH electrocatalyst was determined using x-ray photoelectron spectroscopy (XPS).

Electrochemical measurements. Squidstat plus was used to perform electrochemical measurements using a three-electrode system in the 1 M KOH electrolyte. Working electrodes were OER electrode samples, which had dimensions of . Pt as the reference electrode, and KCl saturated as the counter electrode. The OER activity was measured using linear sweep voltammetry (LSV) curves and Tafel slope is utilized to detect the rate-determining step in a four-electron-transfer process during oxygen evolution. The LSV measurements were performed with a potential range of -0.1 to 1.0 V vs Ref and a scan rate of . Electrochemical impedance spectroscopy (EIS) was used on samples to acquire a better understanding of the OER kinetics, and it was performed from 1 Hz to 1000 kHz . In addition, the stability of the electrode was measured by a chronopotentiometry test and was conducted at current density for 50 hours.

Results and Discussions

The original version of this paper is available on https://www.scientific.net/EI.9.23.pdf

A FE-SEM characterization of pristine and cathodized SSM was performed to demonstrate that a treatment affects the surface morphology, as shown in Fig 1A, 1B. From FE-SEM image with a lowest magnification, it was not possible to clearly show the difference in the surface of SSM before and after treatment. When observing the high magnification, it is found that the SSM surface after cathodization has more irregularly shaped particles attached to the surface than ever before. Fig. 1C, 1D displays FE-SEM images of the electrocatalyst on pristine SSM and cathodized SSM. When observing on cathodized SSM at low magnification, the electrocatalyst was found to have a thicker surface covering and formed higher than pristine SSM in some areas. At high magnification, both pristine SSM and cathodized SSM have the same electrocatalyst growth characteristics. The electrocatalyst that is on the pristine SSM and cathodized SSM was synthesized perpendicular to the surface as randomly bonded plates, and on those plates, it contained a lot of small spherical particles perched on it. Figure 2 shows x-ray photoelectron spectra of Ni 2p, Fe 2p, and O 1s for electrocatalyst. According to the results of XPS, Peak of Ni and Ni found that it was at positions and , respectively. These deconvoluted peak pairs relate to and , respectively. Next , Peak of and found that it was at positions 710.027, 711.709 and , respectively. These deconvoluted peak pairs relate to and , respectively. Next, deconvoluted peaks of O 1 s with centers at are involved for metal oxides and hydroxides, respectively. The binding energies of nickel-ions, ironions and oxygen in this XPS spectra were proven the synthesis of the film on cathodized SSM, in which it has peaks of Ni , and O 1 s that well match the literature reports [16-17].

Fig. 1. Low- and high-resolution FE-SEM image for (A) pristine SSM, (B) cathodized SSM, (C) LDH on SSM, (D) LDH on cathodized SSM.

Fig. 1. Low- and high-resolution FE-SEM image for (A) pristine SSM, (B) cathodized SSM, (C) LDH on SSM, (D) LDH on cathodized SSM.

Fig. 2. XPS spectra of on cathodized-no. 4 SSM : (A) Ni 2p, (B) Fe 2p, and (C) O 1s.

Fig. 2. XPS spectra of on cathodized-no. 4 SSM : (A) Ni 2p, (B) Fe 2p, and (C) O 1s.

A three-electrode setup in a 1 M KOH was used to assess the OER performance of the OER electrode. The LSV can show the difference in the OER activity of the samples. Fig. 3A shows the LSV curve comparison of bare LDH on SSM , and LDH on cathodized SSM. The best samples from all samples are on cathodized SSM, it can be said that cathodization treatment results in a remarkable increase in OER activity. In addition, we have determined the Tafel slope of the bare SSM, LDH on SSM, and LDH on cathodized SSM shown in Fig. 3B. The result of calculating the Tafel slope of the SSM is
, LDH on SSM is , and LDH on cathodized SSM is . As the results show, it can be interpreted that the LDH on cathodized SSM, showing a small Tafel slope, has the fastest electron transfer rate during oxygen evolution.

Fig. 3. Graphs of (A) LSV, (B) Tafel slope, (C) EIS, and (D) Chronoamperometric measurements.

Fig. 3. Graphs of (A) LSV, (B) Tafel slope, (C) EIS, and (D) Chronoamperometric measurements.

The SSM that improves the surface with cathodization was found to have an electrocatalyst that grows higher on the surface than pristine SSM, possibly resulting in an even greater OER activity. In addition, the improvement of SSM surfaces with cathodization also causes OER active site and NiOOH ) to occur on the surface [15], which promotes increased OER activity.

Electrochemical impedance spectroscopy (EIS) was used to determine the behavior of electrode and electrolyte interfaces to obtain additional information about OER kinetics [15-16]. To assess stability, Chronoamperometric measurements were performed. In this work, the EIS and stability measurements were focused on the study of LDH on cathodized SSM, which has the best OER activity. Fig. 3C shows a Nyquist plots, that showed the OER kinetics improved when the SSM was improved with cathodization treatment. The charge transfer resistance ( ) for LDH on cathodized SSM ( ) is lower than for bare SSM ( ) and for cathodized SSM ( ). This suggests that improving the surface of SSM by cathodization treatment and synthesis of the LDH to grow on its surface allows for greater charge transferability during OER, and when both methods are used together, it allows for a greater charge transfer than ever before. Fig. 3D shows chronoamperometry ( ) curve of on cathodized SSM at for 50 hours and demonstrated the high stability of this sample.

We also investigated further on the morphology of the electrocatalyst after stability test. Fig. 4 shows the comparison between LDH on cathodized SSM before and after 50 hours of
stability testing and using the low- and high-resolution FE-SEM to see the electrocatalyst characteristics on the surface. At low magnification, it was found that the highly grown electrocatalyst was detached after testing, but the low-rise electrocatalyst remained well attached to the surface of the SSM surface. At high magnification, it was found that the characteristics of the electrocatalyst remained the same, with its morphology as a plate that rises perpendicular to the surface and is randomly connected, with small spherical particles on those plates.

Fig. 4. Low- and high-resolution FE-SEM image for (A) LDH on cathodized SSM and (B) LDH on cathodized SSM after 50 hours of stability testing.

Fig. 4. Low- and high-resolution FE-SEM image for (A) LDH on cathodized SSM and (B) LDH on cathodized SSM after 50 hours of stability testing.

Fig. 5 shows a Nyquist plot of LDH on cathodized SSM after stability test at 10, 20, 30, 40, and 50 hours to confirm its stability, with the results from the figure showing that the LDH on cathodized SSM has constant OER kinetics for 50 hours. The charge transfer resistance ( ) of LDH on cathodized SSM after 10, 20, 30, 40, and 50 hours is 9.912 , and , respectively. Such results show that it has constant charge transferability and support the results of stability tests well.

Fig. 5. EIS of on cathodized SSM after 10, 20, 30, 40, and 50 hours of stability testing.

Fig. 5. EIS of on cathodized SSM after 10, 20, 30, 40, and 50 hours of stability testing.

Conclusion

The original version of this paper is available on https://www.scientific.net/EI.9.23.pdf

In this work, the effects of cathodization were studied for improving the surface of SSM to greater OER activity for air electrodes in zinc air batteries. The was used as an electrocatalyst, in which it was coated on the surface of SSM samples by one-step chemical bath deposition technique. According to the results, LDH on cathodized SSM (Tafel slope dec ) has a greater OER activity than LDH on SSM (Tafel slope = 171 . The results are due to the fact that electrocatalyst can deposit on the surface of the cathodized SSM, which is thicker than the surface of the pristine SSM, and the surface of cathodized SSM has a greater OER active site and NiOOH . In addition, LDH on cathodized SSM also has high durability ( for 50 hours). Therefore, SSM that improves the surface with the cathodized can be used as a better substrate for binder-free oxygen evolution reaction electrode.

References

The original version of this paper is available on https://www.scientific.net/EI.9.23.pdf

J. Cho, S. Jeong, and Y. Kim, Commercial and research battery technologies for electrical energy storage applications, Progress in Energy and Combustion Science. 48 (2015) 84-101.

M.S. Ghazvini1, G. Pulletikurthi1, T. Cui1, C. Kuhl1, F. Endres, Electrodeposition of zinc from 1-ethyl-3-methylimidazolium acetate-water mixtures: investigations on the applicability of the electrolyte for Zn-air batteries, Journal of The Electrochemical Society. 165(9) (2018) 354.

X. Yan, Y. Ha, R. Wu, Binder-Free Air Electrodes for Rechargeable Zinc-Air Batteries: Recent Progress and Future Perspectives, Small Methods. 5(4) (2021) 2000827.

J. Pan, Y. Xu, H. Yang, Z. Dong, H. Liu, B. Xia, Advanced architectures and relatives of air electrodes in Zn-air batteries, Advanced Science. 5(4) (2018) 1700691.

X. Cai, L. Lai, J. Linb, Z. Shen, Recent advances in air electrodes for Zn-air batteries: electrocatalysis and structural design, Materials Horizons. 4(6) (2017) 945-796.

K. Harting, U. Kunz, T. Turek, Zinc-air batteries: prospects and challenges for future improvement, Zeitschrift für Physikalische Chemie. 226(2) (2012) 151-166.

B. Lee, H. Lee, H. Kim, K. Chung, B. Choa, S. Hyoung, Elucidating the intercalation mechanism of zinc ions into for rechargeable zinc batteries, Chemical communications. 51(45) (2015) 9265-9268.

T. Zhang, Z. Tao, J. Chen, Magnesium-air batteries: from principle to application, Materials Horizons. 1(2) (2014) 196-206.

L. Ma, S. Chen, D. Wang, Q. Yang, F. Mo, G. Liang, N. Li, H. Zhang, J.A. Zapien, C. Zhi, Super-stretchable zinc-air batteries based on an alkaline- tolerant dual-network hydrogel electrolyte, Advanced Energy Materials. 9(12) (2019) 1803046.

B. Zhang, X. Zheng, O. Voznyy, R. Comin, M. Bajdich, M. García-Melchor, L. Han, J. Xu, M. Liu, L. Zheng, F.G. de Arquer, C.T. Dinh, F. Fan, M. Yuan, E. Emre Yassitepe, N. Chen, T. Regier, P. Liu, Y. Li, P. De Luna, A. Janmohamed, H. L Xin, H. Yang, A. Vojvodic, E. Edward H Sargent, Homogeneously dispersed multimetal oxygen-evolving catalysts, Science. 352(6283) (2016) 333-337.

L. Han, S. Dong, E. Wang, Transition-metal (Co, Ni, and Fe)-based electrocatalysts for the water oxidation reaction, Advanced materials. 28(42) (2016) 9266-9291.

F. Liao, X. Zhao, G. Yang, Q. Cheng, L. Mao, L. Chen, Recent advances on two-dimensional NiFe-LDHs and their composites for electrochemical energy conversion and storage, Journal of Alloys and Compounds. 872 (2021) 159649.

S. Niu, Y. Sun, G. Sun, D. Rakov, Y Li, Y Ma, J. Chu, P. Xu, Stepwise electrochemical construction of on Ni foam for enhanced electrocatalytic oxygen evolution, ACS Applied Energy Materials. 2(5) (2019) 3927-3935.

M.B. Stevens, C. D. M. Trang, L.J. Enman, J. Deng, S.W. Boettcher, Reactive Fe-sites in Ni/Fe (oxy) hydroxide are responsible for exceptional oxygen electrocatalysis activity, Journal of the American Chemical Society. 139(33) (2017) 11361-11364.

G. Zhang, L Shen, P. Schmatz, K. Krois, B. J.M. Etzold, Cathodic activated stainless steel mesh as a highly active electrocatalyst for the oxygen evolution reaction with self-healing possibility, Journal of Energy Chemistry. 49 (2020) 153-160.

A.A. Kashale, C. Yi, K. Cheng, J. Guo, Y. Pan, I.P. Chen, Binder-free heterostructured NiFe2O4/NiFe LDH nanosheet composite electrocatalysts for oxygen evolution reactions, ACS Applied Energy Materials. 3(11) (2020) 10831-10840.

Z. Cai, D. Zhou, M Wang, S. Bak, Y. Wu, Z. Wu, Y. Tian, X. Xiong, Y. Li, W. Liu, S. Siahrostami, Y. Kuang, X. Yang, H. Duan, Z. Feng, H. Wang, X. Sun, Introducing Fe2+ into nickel-iron layered double hydroxide: local structure modulated water oxidation activity, Angewandte Chemie. 130(30) (2018) 9536-9540.

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Engineering Innovations, ISSN: 2813-1002, Vol. 9, pp 31-38

doi: 10.4028/p-5yiHYg

© 2024 The Author(s). Published by Trans Tech Publications Ltd, Switzerland.

Submitted:
2023-08-27

Revised:
2023-11-18

Accepted:
2023-11-24

Online:
2024-02-12

Optimal Location of Capacitor in a Radial Distribution System Using New Hybrid Method

The original version of this paper is available on https://www.scientific.net/EI.9.31.pdf

Hassane OUSSEYNI IBRAHIM , Arouna OLOULADE , Moussa GONDA and Francois-Xavier FIFATIN

University Institute of Technology, University Dan Dicko Dankoulodo, of Maradi, BP 465. Maradi, Niger

Polytechnic School of Abomey-Calavi (EPAC), University of Abomey-Calavi, BP 123. Cotonou, Benin

hassane2025@yayoo.fr, olouarou@yahoo.fr, ahmad.nai2011@gmail.com, fifatinf@gmail.com

Keywords: Reactive power compensation; Capacitors; Radial distribution network; Compensator placement; Optimal position

Abstract

Reactive power compensation in the electricity system helps maintain transmission and distribution performance. This can be done by compensator placement; if reactive power is not properly managed, there is a risk of multiplying network losses, overloading facilities and generating unacceptable and unstable voltage levels. This paper solves the problem of optimal position of capacitors in radial distribution network using a new hybrid method combining a new stability index and a genetic algorithm to improve the loss and voltage stability. The Bus Voltage Stability Index BVSI is used to determine the locations and the genetic algorithm GA to calculate the size. The GABVSI analytical-metaheuristic method, compared with existing methods, is more suitable and recommended for operators who are faced with the problem of sizing capacitors to improve the technical performance of their network.

1. Introduction

The original version of this paper is available on https://www.scientific.net/EI.9.31.pdf

Voltage is regulated on the radial distribution network by means of load tap changers (LTC) in HV/MV source substations, the placement of capacitors in distribution substations, the positioning of flexible alternating current transmission systems (FACTS), and so on. In view of the rapid growth in loads on electrical installations, some of the above-mentioned devices are proving to be slow and ineffective in monitoring changes in these loads and dynamically adjusting voltage. For example, LTC are made up of coils positioned on the primary windings of transformers in HV/MV source substations. Their role is to modify the transformation ratio to improve the secondary voltage if the load changes. the transition from one turn to another is always accompanied by electric arcs, which are the cause of certain equipment failures recorded on these types of transformers. In the event of rapid load growth, the controllers freeze and are no longer able to adjust effectively to correct the impact of load growth. Capacitors placed in HV/MV source substations or in MV/LV distribution substations, with the aim of providing reactive power to compensate for the overall network, do not effectively and sustainably improve the technical performance of electricity networks. These empirical methods of capacitor positioning do not demonstrate their effectiveness. Consequently, the reagent must be supplied locally and optimally to the consumer loads by reconfiguring the shunt capacitors. The positioning and operating costs of FACTS devices in networks raise issues that need to be studied in order to highlight their technical contribution and profitability in terms of their application in distribution networks. There are several methods in the literature for solving these problems. The effectiveness obtained varies from one method to another. This paper will study the optimal positioning of capacitors, using a new hybrid method, to improve the technical performance of the radial distribution system. There are many different algorithms for placing capacitors in distribution systems [1]. The total number of publications specific to capacitor allocation problems is close to . The methods developed include analytical methods, numerical programming, heuristic methods, metaheuristic methods based on artificial intelligence and a combination of
techniques [4]. These latest have become attractive in power system optimisation techniques, and in most cases combine a stability index and a metaheuristic.

2. Problem Formulation for Optimal Capacitor Sizing

The original version of this paper is available on https://www.scientific.net/EI.9.31.pdf

The aim of installing capacitors in distribution networks is to improve the technical and environmental reliability of the power system. This problem is formulated as that of a multi-objective function with several criteria and constraints, including the stability index, the cost of lost energy, the voltage at the nodes, the current in the branches, and so on. The optimisation criteria and constraints are described below:

2.1. Bus voltage stability index

BVSI, a new concept defined in reference [5], BVSI is used to designate candidate buses for capacitor placement. The exploration zone and the optimisation process are considerably reduced

The nodes with the lowest BVSI will be given priority as candidates for the installation of compensation devices.

2.2. Objective function

The proposed objective function for the optimal capacitor placement problem is to minimize the total cost, which is determined by the following equation:

Where X represents the device used, which may be a capacitor or other compensator. In this paper we will use capacitors, the annual cost of which is taken from reference [6].

2.3. Contraints

Voltage Deviation Limit [6]:

Line Current Limits [7]:

Reactive power compensation

It is impossible for the capacitor to remain connected, as the reactive power is not only proportional to the square of the voltage at its terminals, but will also be injected constantly even in normal operation, leading to a risk of overcompensation, unacceptable voltage amplitude or premature collapse of the system voltage. To limit these inconveniences, the constraints on the total reactive power injected and the overall power factor of the system will be defined as follows [8]:

2.4. Net savings

The net savings is the difference between total energy loss cost before installation and total energy loss cost and annual capacitor after installation is given by Eq. (9) as follows:

3. Load Flow

The original version of this paper is available on https://www.scientific.net/EI.9.31.pdf

Backward/forward sweep load flow, proposed by Jen-Hao Teng [9], is developed on the Matlab platform for calculating the load flow and the BVSI stability index of the various nodes.
Calculation of current injections at the different nodes as follows:

Calculation of branch currents by:

Calculation of the voltage drops in each branch by:

Calculation of new nodal voltages, by:

Calculate the BVSI at each node, by:

Calculate total active loss:

Calculate total reactive loss:

4. Hybrid Approach GA-BVSI

The original version of this paper is available on https://www.scientific.net/EI.9.31.pdf

The contextualised genetic algorithm is used to optimally size the capacitor. The positions of these capacitors on the network are identified using the BVSI concept designed for this purpose. This hybrid approach consists of creating a population of N chains around the nodes identified by the BVSI so that GA starts in an ideal zone in the solution space. The individuals in the population created are evaluated by calling up the objective function. The best individuals are then selected (roulette) in pairs to reproduce a generation of individuals by running the crossover and mutation operators with a probability of ( 0.8 ) and ( 0.3 ) respectively, which will be reassessed for the next generation. In this way, the evolutionary loop is repeated until the natural goal is reached. Based on the approximation and research carried out, the pseudo-code and GA-BVSI flowchart in figure 1, for this new approach to optimise the capacitor positioning process are presented below.

Pseudo-code GA-BVSI for compensator placement

The original version of this paper is available on https://www.scientific.net/EI.9.31.pdf

2 Identify candidate buses for capacitor placement using BVSI;
3 Randomly generate the initial population from the group of BVSI buses identified;

5 While AND stop condition not satisfied Do
6 Evaluate each individual in the population according to the objective function;
7 Select parents from the selected population;
8 Produce and evaluate the offspring of parents selected by crossover and mutation;
9 Replacing parents with offspring;

End
11 Return the best population.

Fig. 1. Flow chart of GA-BVSI.

Fig. 1. Flow chart of GA-BVSI.

5. Results and Discussion

The original version of this paper is available on https://www.scientific.net/EI.9.31.pdf

The superiority of the GA proposed with BVSI is implemented with the IEEE 69-bus test system shown in figure 2. This network comprises 69 buses and 68 branches with a total active and reactive
load of 3.80 MW and 2.69 MVAr respectively. The average operating voltage of the network is 12.66 kV . The line and bus parameters are taken from reference [10]. The proposed hybrid algorithm was created using Matlab. The initial active and reactive power losses without compensator are 224.8949 kW and 101.7 kVAr respectively. The minimum voltage is at node 65 . Table 1 shows the results of this positioning optimisation compared with references [11], [12] and [13]. It is observed that the total capacitor size evaluated by the proposed GA BVSI method is 1550 kVAr partitioned at node and node . This size is the smallest and the most optimal to reduce to the lowest value the total cost due to the proposed objective function, i.e. compared to the values obtained by the aforementioned references. Similarly, the percentage of net savings with GA-BVSI is the highest compared with the other techniques, at . Network losses fell from 224.8949 kW in the initial case to 146.5 kW after compensation, a reduction of . In addition, the minimum voltage has been improved from 0.9092 p.u. to 0.9306 p.u. and the maximum current reduced from 386.2727 A to 327.3817 A. Note that in reference [12], using PLI, the authors have evaluated a larger capacitor size of 1650 KVAr partitioned over 5 nodes, the losses are reduced to 146.13 kW and the minimum voltage improved to 0.9327 p.u. However, these differences are relatively insignificant and we can deduce from them the reliability and performance of the GABVSI. The system voltage profile is shown in Figure 3 using the installed capacitors. Table 2 shows the settings of the objective function for optimization.

Fig. 2. Single-line diagram of an IEEE standard 69-bus network

Fig. 2. Single-line diagram of an IEEE standard 69-bus network

Table 1. Results for optimal placement of capacitors on a 69-bus system

Items | Un-compensated | Compensated
|  | Fuzzy-GA [11] | DE-LSF [12] | PSO- LSF[13] | DE-PLI [12] | GA-BVSI
Total losses (kW) | 224.8949 | 156.62 | 151.3763 | 152.48 | 146.13 | 146.5
Loss reduction (%) | - | 30.4 | 32.7 | 32.2 | 35.02 | 34.85
Minimum voltage | 0.9092 | 0.9369 | 0.9311 | - | 0.9327 | 0.9306
Maximum Current (A): | 386.2727 | - | - | - | - | 327.3817
Optimal location |  | 59 | 100 | 57 | 150 | 46 | 241 | 61 | 950 | 61 | 1250
and size in kVAr |  | 61 | 700 | 58 | 50 | 47 | 365 | 64 | 200 | 17 | 300
|  | 64 | 800 | 61 | 1000 | 50 | 1015 | 59 | 150 | - | -
|  | - | - | 60 | 150 | - | - | 65 | 50 | - | -
|  | - | - | 59 | 100 | - | - | 21 | 300 | - | -
Total kVAr |  | 1600 | 1450 | 1621 | 1650 | 1550
Annual cost($/year) | 118,204.8 | 90119.5 | 88913.4 | 88606.5 | 86758.8 | 84250.4
Net saving ($/year) | - | 28085.3 | 29291.4 | 29598.3 | 31446 | 33954.4
% saving | - | 23.8 | 24.78 | 25.03 | 26.6 | 28.72

Fig. 3. Voltage profiles of the 69-bus system before and after compensation

Fig. 3. Voltage profiles of the 69-bus system before and after compensation

Table 2. Objective function parameter settings for optimization

Item | Proposed setting
Number of generations | 150
Number of individuals per population | 750
Percentage of crossover | 0.8
Percentage of mutation | 0.3
Jmax | 520A
KI | $1000/location
KO | $300/year/location
Kc | $ 3/kVAr
KT | 1
Ke | $0.06/kWh
PFmin | 0.9
PFmax | 1
T | 8760 h
μ | 1
λ | 2

6. Conclusions

The original version of this paper is available on https://www.scientific.net/EI.9.31.pdf

The GA-BVSI hybrid method has been developed for the optimum positioning of capacitors in a radial distribution system. Given its accessibility, technical performance and ability to identify weak points in an electrical system, its use can be strongly recommended to distribution network operators. This scientific contribution will provide electricity companies with practical solutions, in particular the reconfiguration of capacitor positioning. Optimal placement and sizing of a shunt capacitor increases voltage stability, and the positioning of multi-capacitors is not expensive. Shunt capacitors are relatively inexpensive and easy to install and maintain. However, they have less function and control over network parameters and have major inconveniences.
In addition, the GA-BVSI analytical-metaheuristic method can be used to optimise the placement of FACTS devices.

Nomenclature

The original version of this paper is available on https://www.scientific.net/EI.9.31.pdf

Item | Proposed setting
Number of generations | 150
Number of individuals per population | 750
Percentage of crossover | 0.8
Percentage of mutation | 0.3
Jmax | 520A
KI | $1000/location
KO | $300/year/location
Kc | $ 3/kVAr
KT | 1
Ke | $0.06/kWh
PFmin | 0.9
PFmax | 1
T | 8760 h
μ | 1
λ | 2

Acknowledgement

The original version of this paper is available on https://www.scientific.net/EI.9.31.pdf

The authors gratefully acknowledge the reviewers of this paper for their valuable advice and guidance. This research has not been funded in any way.

Competing Interests

The original version of this paper is available on https://www.scientific.net/EI.9.31.pdf

Authors have declared that no competing interests exist.
Ethical Approval (not applicable)

Availability of Data and Materials

The original version of this paper is available on https://www.scientific.net/EI.9.31.pdf

The simulations were carried out with Matlab R2021a.

References

The original version of this paper is available on https://www.scientific.net/EI.9.31.pdf

A. K. Bhargava, M Rani, Sweta, Optimal sizing and placement of capacitor on radial distribution system using genetic algorithm, Materials Today: Proceedings, 2023, ISSN 2214-7853, HTTPS://DOI.ORG/10.1016/J.MATPR.2023.03.347

Capacitor Subcommittee of the IEEE Transmission and Distribution Committee, «Bibliography on power capacitors 1975-1980», IEEE Trans. Power Apparatus and Systems, vol. 102, , p. 2331-2334, juill. 1983.

IEEE VAR Management Working Group of the IEEE System Control Subcommittee, «Bibliography on reactive power and voltage control», IEEE Trans. Power Systems, vol. 2, 2, p. 361-370, mai 1997.

H. N. Ng, M. M. A. Salama, et A. Y. Chikhani, «Classification of capacitor allocation techniques », IEEE Transactions on Power Delivery, vol. 15, 1, p. 387-392, janv. 2000, doi: doi: 10.1109/61.847278.

H. O. Ibrahim, F. -X. Fifatin, A. Oloulade, A. M. Imano and A. K. Vianou, "Positioning of multicapacitors in a radial distribution network using new analytical methods," 2021 International Conference on Electrical, Computer and Energy Technologies (ICECET), 2021, pp. 1-6, doi: 10.1109/ICECET52533.2021.9698665.

Y. Abdelaziz, E.S. Ali, S.M. Abd Elazim, Optimal sizing and locations of capacitors in radial distribution systems via flower pollination optimization algorithm and power loss index, Engineering Science and Technology, an International Journal, Volume 19, Issue 1, 2016, Pages 610-618, ISSN 2215-0986, .

Saravanan M, Slochanal SMR, Venkatesh P, Abraham JPS. Application of particle swarm optimization technique for optimal location of FACTS devices considering cost of installation and system loadability. Electr Power Syst Res 2007; 77 (3-4): 276-83.

Tahir MJ, Rasheed MB, Rahmat MK. Optimal Placement of Capacitors in Radial Distribution Grids via Enhanced Modified Particle Swarm Optimization. Energies. 2022; 15(7):2452.

T. Jen-Hao, «A direct approach for distribution system load flow solutions», IEEE Transactions on Power Delivery, vol. 18, 3, p. 882-887, juill. 2003, doi: 10.1109/TPWRD. 2003.813818.

S. A. Taher et S. A. Afsari, «Optimal location and sizing of DSTATCOM in distribution systems by immune algorithm», International Journal of Electrical Power & Energy Systems, vol. 60, p. 34-44, 2014.

D. Das, Optimal placement of capacitors in radial distribution system using a Fuzzy-GA method, Int. J. Electr. Power Energy Syst. 30 (2008) 361-367.

A. Elfergany, Optimal capacitor allocations using evolutionary algorithm, IET Proc. Generation Transm. Distrib. 7 (2013) 593-601.

K. Prakash, M. Sydulu, Particle swarm optimization based capacitor placement on radial distribution systems, IEEE Power Engineering Society General Meeting, 24-28 June 2007, pp.1-5, 2007.

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Engineering Innovations, ISSN: 2813-1002, Vol. 9, pp 39-44

doi: 10.4028/p-osi7Ns

© 2024 The Author(s). Published by Trans Tech Publications Ltd, Switzerland.

Submitted:
2023-06-21

Revised:
2023-08-20

Accepted:
2023-08-30

Online:
2024-02-12

Design and Implementation of Automatic Aiming and Locking System

The original version of this paper is available on https://www.scientific.net/EI.9.39.pdf

Ping-Cheng Chen , Chung-Long Pan

¹Department of Intelligent Network Technology, I-Shou University, No.1, Sec. 1, Syuecheng Rd., Dashu District, Kaohsiung City 84001, Taiwan

Department of Electrical Engineering, I-Shou University, No.1, Sec. 1, Syuecheng Rd., Dashu District, Kaohsiung City 84001, Taiwan

chen1113@isu.edu.tw, ptl@isu.edu.tw,

Keywords: OpenCV, Face Recognition, Cascading Classifier, Robot arm, automatic aiming, automatic locking.

Abstract

In this article, the training parameters of cascade classifiers for specific targets (such as human faces and palms) are obtained by using the program training function provided by OpenCV and adjusting parameters such as the number of positive and negative samples and ratios to achieve better recognition results. Finally, the aiming and locking system for specific targets is constructed by combining recognition, algorithm, and robot control capabilities.

Introduction

The original version of this paper is available on https://www.scientific.net/EI.9.39.pdf

Facial recognition technology has been studied since 1872 in psychology research [1] [2] [3], and engineering-related studies began in the 1960s [4] [5]. However, the real research on machine automatic recognition of human faces began in the 1970s with Kanade [6] and Kelly's [7] research reports. In recent years, due to the improvement of computer processing power and various machine learning algorithms [8][9], facial recognition technology has matured and has been widely used in various fields such as airports, attendance checks, and mobile phone security.

In this article, we aim to replace human eyes with computer vision, human brains with programmatic judgments, and human arms with robotic arms to build an automatic targeting and locking system. OpenCV is used to train specific target classifiers, and optimal parameters are used to obtain better recognition results. The recognition results are then used with inverse kinematics algorithms to obtain the rotation angles of the robotic arm joints, thereby controlling the arm to target and lock onto the target object. Thus, an automatic targeting system is established and implemented.

In summary, this study provides a valuable reference for research and application in related fields by proposing a training parameter adjustment strategy and performance analysis for cascade classifiers, as well as an automatic aiming and locking system based on this classifier.

Performance Analysis of Cascading Classifiers under different Training Parameters

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Cascading classifiers are classifiers with HARR features and are trained by waterfall algorithms. With the help of faceCascade.dectedMultiScale function provided by OpenCV cascading classifiers can detect the presence of a specific target in the image. The training method is by providing a certain number of positive photos (the image contains the target to be detected) and the negative photos (the image does not contain the target to be detected) generated by the opencv_traincascade.exe program. In the application of recognizing a specific face, due to the complex characteristics of the human face, the discriminating ability of the trained classifier is greatly affected by the type of positive and negative photo, quality, brightness, quantity, and other factors.
Figure 1. shows the possible result of the classifier identifying the specific object in the image: a. The target object in the image is marked. b. The target object in the image is not marked. c. The nontarget object in the image is marked.

Fig. 1. The possible result of the classifier identifying the specific object in the image

Fig. 1. The possible result of the classifier identifying the specific object in the image

In this study, different numbers of positive samples, negative samples, and different types of negative samples are selected in the training of cascade classifiers. The trained classifier is then tested with a set of samples (the samples contains 82 target's photos, 113 others human and background). For the convenience of explanation, the following parameters are defined:

Identification rate: (number of identified targets in the samples / number of targets in the samples). Ideal value: 100%

False positive rate: (the number of identified as non-targets in the samples / the number of non-targets in the samples) that is, the misjudgment of others as you. Ideal value: 0%

Figure 2 and Figure 3 show the identification rate and false positive rate of various classifiers under different training parameters.

Fig. 2. The identification rate of various classifiers

Fig. 2. The identification rate of various classifiers

Fig. 3. The false positive rate of various classifiers

Fig. 3. The false positive rate of various classifiers

Several conclusions can be drawn from the results:

A larger number of positive samples leads to a higher identification rate. This is due to the increased quantity of positive samples, which provides a greater pool of reference features. As a result, the classifier can more effectively identify specific targets.

A higher quantity of negative samples leads to a reduced false positive rate. This occurs because the distinct characteristics of other samples are excluded, minimizing the likelihood of incorrect judgments.

A larger quantity of positive films increases both the identification rate and the false positive rate. This phenomenon arises from the fact that relatives may share similar characteristics with the samples.

Training a classifier for a specific target "human face"

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Based on the conclusion above, a classifier for identifying "human faces" was trained with the training conditions of 10,000 positive images and 2,500 negative images, and the actual identification results were verified. The results obtained are shown in the Table 1:

Table 1. The actual identification results

object to be identified (human face) | The recognition rate
One thousand images containing faces | 98.15%
In actual environment, 100 personnel passed by (1). | 95%
In actual environment, 100 personnel passed by. (2) | 95%
In actual environment, 100 personnel passed by. (3) | 94%
In actual environment, 100 personnel passed by. (4) | 93%
In actual environment, 100 personel passed by. (5) | 95%

According to the results in Table 1, it shows that in practical application, the recognition results will be affected by environmental variables such as lighting, angles, movements, and different individuals, resulting in a decrease in overall recognition rate to around 94%.

Design and Implementation of Automatic Aiming and Locking System

The original version of this paper is available on https://www.scientific.net/EI.9.39.pdf

An automatic aiming system can be divided into two main parts: image recognition and motion control. First, an image of the environment is captured using a camera, and image processing techniques are used to identify the target and determine its position. Next, the system calculates the distance, direction, and angle to the target based on its position, and uses a mechanical arm control component to achieve aiming. This automatic aiming system can be applied in military, industrial, and aviation fields, improving operational efficiency and accuracy while reducing personnel risk and fatigue.

The operating procedure of the automatic targeting and locking system is shown in Figure 4, which is explained as follows:

When the target enters the camera monitoring range,

The classifier recognizes the target and detects its location.

The inverse kinematics calculate the rotation angles of each joint of the robotic arm.

The robotic arm is controlled to aim at the target.

If the target moves,

Repeat .

Fig. 4. The operating procedure of the automatic targeting and locking system

Fig. 4. The operating procedure of the automatic targeting and locking system

Figure 5 illustrates a sequence of images during the system operation. In the images, it can be observed that as the face moves, the movement of the robotic arm consistently directs the laser pointer attached to the arm to continuously aim at the face. This demonstrates the effective operation of the system.

Fig.5. The actual performance of the system during operation

Fig.5. The actual performance of the system during operation

Training a classifier for a specific target "human palm"

The original version of this paper is available on https://www.scientific.net/EI.9.39.pdf

Based on the conclusion above, a classifier for identifying " palms " was trained with the training conditions of 10,000 positive images and 2,500 negative images, and the actual identification results were verified. The results obtained are shown in the Table 2:

Table 2. The actual identification results

object to be identified (human palm) | The recognition rate
One thousand images containing human palm | 98.8%
In actual environment, One hundred passes of the target. (1). | 97%
In actual environment, One hundred passes of the target. (2) | 96%
In actual environment, One hundred passes of the target. (3) | 96%
In actual environment, One hundred passes of the target. (4) | 97%
In actual environment, One hundred passes of the target. (5) | 96%

Compared to human faces, the geometric structure and features of palms are relatively simplier, and the recognition result can be more accurate, reaching around .

Figure 6 illustrates a sequence of images during the system operation. In the images, it can be observed that as the palm moves, the movement of the robotic arm consistently directs the laser pointer attached to the arm to continuously aim at the palm. This demonstrates the effective operation of the system.

Fig. 6. The actual performance of the system during operation

Fig. 6. The actual performance of the system during operation

Conclusion

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In this study, we first searched for optimal training parameters to train the classifier and then locked onto specific objects to train the classifier. In actual recognition, we were able to achieve recognition rates of over for human faces, for human palm. Through recognition, algorithms, and arm control, a practical automatic aiming system can be formed. This system architecture can be applied to actual applications such as automatic aiming, automatic classification, security, and defense industries.

References

The original version of this paper is available on https://www.scientific.net/EI.9.39.pdf

C. Darwin. The Expression of the Emotions in Man and Animals. John Murray, London, 1872.

I. Bruner and R. Tagiuri. The perception of people. In: G. Lindzey, editor, Handbook of Social Psychology, volume 2, pages 634-654, Reading, MA, 1954. Addison-Wesley.

F. Galton. Personal identification and description. Nature, pages 173-188, 1888.

M. Bledsoe. The model method in facial recognition. Technical Report PRI 15, Panoramic Research Inc., Palo Alto, CA, 1964.

P. Ekman, editor. Charles Darwin's THE EXPRESSION OF THE EMOTIONS IN MAN AND ANIMALS. HarperCollins and Oxford University Press, London and New York, 3rd edition, 1998.

T. Kanade. Computer Recognition of Human Faces. Birkhauser, 1973.

M. Kelly. Visual identification of people by computer. Technical Report AI 130, Stanford, CA, 1970.

Paul Viola and Michanel J. Jones. Rubust real-time object detection. In Proc. of IEEE Workshop on Statistical and Computational Theories of Vision,2001.

P. Voila and M. Jones. Robust real-time object detection. Int'L. J. Computer Vision, 57 (2): 137-154, 2002.

This ePub file was created using machine-generated methods and automated software to convert the source text into an ePub format and may contain formatting inconsistencies from the original version. Formatting may vary depending on the device used.

The original version of this eBook is available on https://www.scientific.net/book/engineering-innovations-vol-9/978-3-0364-1504-8

Engineering Innovations, ISSN: 2813-1002, Vol. 9, pp 45-56

doi: 10.4028/p-8VyoJx

© 2024 The Author(s). Published by Trans Tech Publications Ltd, Switzerland.

Submitted:
2022-11-10

Revised:
2023-03-12

Accepted:
2023-06-06

Online:
2024-02-12

System Dynamics Model to Improve Logistics Cost Efficiency in Fertilizer Distribution Outside Java (Gresik - Medan)

The original version of this paper is available on https://www.scientific.net/EI.9.45.pdf

Yoke Candra Katon , Dhimas Widhi Handani , Ketut Buda Artana , Mikha Asta Lumirang , Putu Widhi Aprilia

¹Interdiciplinary School of Management Technology, Institut Teknologi Sepuluh Nopember, Surabaya, Indonesia

Department of Marine Engineering, Institut Teknologi Sepuluh Nopember, Surabaya, Indonesia

yokekaton@gmail.com, dhimas_mareng@yahoo.com, ketutbuda@its.ac.id, Mikhalumirang17@gmail.com, putuwidhiaprilia@gmail.com

Keywords: Efficiency Cost, Fertilizer, Logistic, System Dynamics

Abstract

Within the vast development of globalization, companies are encouraged to increase competitiveness level, in order to survive in the market. One certain way to stay competitive and retain customers is to provide such products with reasonable selling prices. Supply chain costs have a great influence upon the cost of the final product; therefore, companies are suggested to continuously improve supply chain processes regarding reducing overall costs. One industry indicated with high supply chain costs is the fertilizer industry, referring to the fact that it has a nationwide distribution system. For countries which regulate fertilizer as a subsidized product, companies must be able to provide fertilizer at an efficient price to maintain prevalence in the market. Currently, the problem faced by one of the fertilizer companies is an indication of expensive logistics costs for fertilizer distribution outside Java. The most expensive logistics costs are owned by the Medan area with variations in bulk transportation. This problem can be solved if there are alternative economic scenario designs in accordance with capabilities. The purpose of this research is to provide alternative scenarios, simulate those scenarios, and choose the most efficient scenario. The method used in this research is system dynamics and 12 scenarios were generated in this paper. Selection of the appropriate ship size and type of heavy equipment for loading and unloading cargo from those scenarios can impact in energy saving/fuel consumption and minimize operational costs. Beside cost, fertilizer deficit is also a consideration in scenario selection. From the result, scenario 3 has the lowest distribution costs with a total cost is Rp. 241,513 and the total fertilizer deficit is 0 tons, so scenario 3 is the selected alternative scenario to minimize operational cost.

Introduction

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A low-cost strategy and a fast response to market fulfillment are very important challenges in today's world of goods and services industry. In general, all companies aim to increase profits as many as possible and minimize expenses, but many expenditure problems are often encountered. And often the biggest expenses lie in the distribution process to customers [1]. This is commonly known as logistics management which is part of Supply Chain Management (SCM).

SCM is a series of planning, coordinating, and controlling all business processes and activities in the Supply Chain to create the best consumer value at an efficient cost while still meeting all the needs of other stakeholders in the Supply Chain [2]. Meanwhile, logistics management is part of SCM which is focused on the flow of finished goods that are connected to the place of origin and destination to meet the needs of customers [3]. Both of these are very important elements to improve cost efficiency, and to minimize a company's expenses [3,4].

PT. X is a company engaged in the fertilizer sector. Products from PT. X are exported abroad, and some are also marketed domestically and will be distributed to several regions. Many new competitors from abroad have started to enter Indonesia. In 2019, fertilizer imports reached 6.134 million tons from more than 19 countries [5]. Fertilizer producers from abroad dare to compete with local fertilizer producers at competitive prices. This makes domestic fertilizer producers have to improve to be able
to compete. All activities carried out by PT. X to meet customer needs still cannot be separated from costs. Starting from the initial arrival of the ship's raw materials, then processed into finished fertilizer, to delivery using ships and trucks to meet the needs in an area.

Recently, PT. X wanted to reduce logistics costs because it indicated that there was an expensive cost of transporting fertilizer to marketing warehouses where the fertilizer was transported by ship. In terms of quantity, PT. X had a higher share in Java Island to distribute fertilizers when compared to the total distribution outside Java. However, there was a problem that the logistics costs of distributing fertilizer to Outside Java are much higher. From the data owned by PT. X, it appears that the highest logistics costs lay in the cost of distributing fertilizer from PT. X warehouses to Distribution Center (DC) warehouses outside Java which reached 731.5 billion rupiah or equivalent to of the total cost [6]. The following is data on logistics expenditures owned by PT. X. The delivery of fertilizer to areas outside Java is divided into 3 variations of shipments consisting of bulk, in-bag, and container. In the delivery demand data, four regions have large quantities listed in tons, and the Medan area is the area which obtains the highest demand by having all three variations of the demand for fertilizers. Of the three variations of delivery which are requested from the Medan Region, the Bulk variation is the largest demand from that area. This problem can be solved by designing an alternative fertilizer distribution design that is economical and following the capabilities.

The objective of this work is to explore the application of System Dynamics Modelling in logistic and supply chain management. System Dynamics methodology was introduced by Forrester as a modelling and simulation for long - term decision making in dynamic industrial management cases [7]. Since then, SD has been used to address numerous issues with business strategy and policy [810]. Various researchers have been documented publications using SDM in supply chain modelling, but most of them refer to forward logistics [11].

In this paper, several designed an alternative fertilizer distribution were proposed to solve the problem of inefficiency in distributing fertilizer from origin warehouse to destination warehouse. Therefore, twelve alternative scenarios of fertilizer distribution are generated in this paper so that they can be analyzed and simulated using system dynamics.

Methodology

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In this paper, System Dynamics Model (SDM) are used to evaluate the potential reduction in fertilizer distribution cost in PT. X and in order to help management PT. X make effective strategic decisions. SDM is one widely used modelling tools to develop models that are based on historical data and several sub systems to reflect the dynamic relationship between important variables in each system [12,13]. In general, SDM consists of concept of development step, modelling step, simulation model step, and validation & verification of simulation results [14]. The proposed methodological procedure is presented by the diagram in Figure 1. After problem identification and literature study, data will be collected, and several alternative scenarios will be generated. Then, several scenarios simulated in Powersim Studio 8. At the end, validation and analysis will be carried out as well as compiling conclusions and suggestions for this research.

Fig. 1. Methodology

Fig. 1. Methodology

A. Supply Chain Alternatif Scenario Development

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In the process of simulation, it takes several scenarios of fertilizer distribution which will be compared, so that it will emerge which scenario is the most efficient in terms of cost. The scenario made is an alternative scenario that adapts to real done by PT. X except in the aspect of ships. The ship is chosen randomly to find which ship capacity is the most efficient in terms of cost. The cost aspect of the ship will be determined from the operational cost of selected ship.

B. Causal Loop Diagram

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Causal Loop Diagram (CLD) in dynamic system modeling is part of systems thinking that is used to review several types of systems and the same perspective, thus forming a diagram. According to [9] the Causal Loop Diagram (CLD) is a representation of the conceptualization of the system dynamics model to be built. Through CLD the system dynamics model to be developed is explained by showing the causal relationship between the variables entered the model before next to the model development stage. By showing each relationship between variables in the system, CLD can show the hypothetical results of a system modeled with system dynamics.
In a CLD, the relationship between two variables is represented by an arrow that marks the relationship between the two variables. In addition, there is also a positive sign ( + ) and a negative sign (-) which refer to how the two variables are related. The positive sign shows a positive effect, meaning that if there is a change in a certain variable, it will affect the other variables which are associated with a positive arrow and will change in the same direction. On the other hand, the negative sign indicates a negative effect where if there is a change in a certain variable it will affect other variables but in a different direction of change [15].

C. Stock And Flow Diagram

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The stock flow diagram is a concept of a system dynamics model that serves to represent the stock and flow of a particular system [9]. Stock and flow diagrams can be described as a container where the flow of water enters through the valve and the volume of water can be reduced by opening the
valve in the container. The container is represented as a 'stock' in a stock flow diagram whereas the flow of water flowing either in or out of a tube distorted by a valve is a 'flow' in a stock flow diagram.

D. Model Verification and Validation

The original version of this paper is available on https://www.scientific.net/EI.9.45.pdf

Verification indicates that the developed model produced is a conceptual model, and validation is a step to determine one of the successful models with its implementation representing real conditions or not [16]. In this study, 3 (three) methods would be used to validate the simulation:

Structural Scoring Test

This test aims to determine whether the structural model has represented the conceptual model by containing all the same elements, relations, and events or not [16]. The conceptual model refers to the Causal Loop Diagram.
2. Dimensional Consistency Test

It is important that the units of measurement for the variables on both sides of the equation are the same. This test also checks whether the dimensions of the variables in the model correspond to the units in which they can correctly express the real variables that exist in the company [17].
3. Extreme Condition Test

This test is intended to test the model that has been made with predetermined limits on the causal loop. When the simulation takes place, a variable will be entered in an extreme value to see the attachment between one variable and another [17].

E. Result Verification and Validation

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At this stage, validation of the results that have been obtained will be carried out. The simulation results will be matched with the results from real data so that the actual system output that occurs in real conditions also occurs in the simulation conditions that have been made. When the output of the simulation and the real conditions are the same, the results of the alternative scenarios in the simulation can be declared valid.

Results and Discussion

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After the required data is obtained, the next step is to create several alternative scenarios that adjust the real conditions of PT. X and develop it on aspects of ships that have different variations in cargo to compare which of each scenario has the most efficient cost. This aspect of the cost of the ship will be determined from the cost of fuel incurred to move variations in shiploads. The following are 12 forms of logistics scenarios that will be simulated using system dynamics to see which scenario is the most cost- effective. Alternative scenarios can be seen in Table 1.

Table 1. Alternative Scenarios

Scenario | Loading | Ships Payload | Unloading | Warehouse
1 | Conveyor | 16,800 | Truck and Crane | DC warehouse
2 | Conveyor | 26,100 | Truck and Crane | DC warehouse
3 | Conveyor | 34,300 | Truck and Crane | DC warehouse
4 | Conveyor | 52,200 | Truck and Crane | DC warehouse
5 | Conveyor | 41,400 | Truck and Crane | DC warehouse
6 | Conveyor | 25,200 | Truck and Crane | DC warehouse
7 | Truck and Crane | 16,800 | Truck and Crane | DC warehouse
8 | Truck and Crane | 26,100 | Truck and Crane | DC warehouse
9 | Truck and Crane | 34,300 | Truck and Crane | DC warehouse
10 | Truck and Crane | 52,200 | Truck and Crane | DC warehouse
11 | Truck and Crane | 41,400 | Truck and Crane | DC warehouse
12 | Truck and Crane | 25,200 | Truck and Crane | DC warehouse

After the alternative scenario has been created, the next step is to model the condition of the existing using the variables shown by the causal loop diagram. These variables must be determined in advance because they are needed to formulate the diagram. Then the causal loop diagram will serve as a guide for creating the basic model. The basic model is a model that already represents the existing system in fertilizer distribution. The causal loop diagram that will be made is a diagram that shows the growth of fertilizer distribution costs carried out. The conceptual model of fertilizer distribution costs can be seen in Figure 2.

Fig. 2. Causal Loop Fertilizer Distribution Diagram

Fig. 2. Causal Loop Fertilizer Distribution Diagram

In the causal loop modeling the cost of sending fertilizer from PT. X to Medan Distribution Centre, there are 4 main variables, namely PT. X outbound costs, Ship freight costs, warehouse rental costs, and DC outbound costs. In the main variable, there are also sub-variables that influence each other as follows.

PT. X Outbond Cost

PT. X outbound costs are costs incurred to transport PT. X to Medan port. Aspects in this cost include heavy equipment costs, which are heavy equipment operational costs such as pay loader costs to lift bulk fertilizer to trucks, and also conveyor operating costs, trucking costs, which are costs for transporting bulk fertilizer from the PT. X warehouse to the port using trucks, and PBM costs, which are the costs of transporting fertilizer from the truck or dock to the ship.

2. Ship Freight Cost

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Ship freight costs are costs that will be incurred to send fertilizer from PT. X port to Medan port. Aspects that include ship freight include the cost of fuel oil to move the main engine and auxiliary engine when the ship is sailing. In addition to this, fuel costs also include lubricants used by the main engine and auxiliary engines on the selected ship.

3. Warehouse Rental Cost

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Warehouse rental costs are costs that will be incurred to rent a place according to the required fertilizer capacity. In addition to capacity, other costs that need to be incurred are for managing the stock of fertilizer in the warehouse so that it does not get damaged quickly.

DC Outbond Cost

Outbound DC costs are costs incurred to transport fertilizer products from PT. X from DC port to DC warehouse. Aspects in this cost include PBM costs, which are costs for transporting fertilizer from ships or docks to trucks using shore cranes or vessel cranes, and trucking costs, which are costs for transporting bulk fertilizer from DC port to DC warehouse using trucks.

After making a Causal Loop Diagram and knowing all its relationships with all variables, the next step is to make a Stock and Flow Diagram. In each scenario, there are 2 (two) kinds of Stock and Flow Diagrams. First, Stock and Flow Diagram discuss the flow process of fertilizer distribution in PT. X and the second Stock and Flow Diagram discuss the estimation cost from this scenario. From the existing data, 12 Stock and Flow Diagrams were generated in this paper. Stock and Flow Diagrams are presented in Figure 3 and Figure 4.

In the Stock and Flow Diagram, the distribution is divided into several parts which indicate that the fertilizer distribution runs from the PT. X warehouse to DC Medan. Starting from the stock in the warehouse, loading fertilizer to the ship using a conveyor, ships with varying payloads, unloading fertilizer using a shore crane and expedition to the DC warehouse using a truck. The formula used from the Stock and Flow Diagram above is the "IF", "AND" and "OR" formulas.

Fig. 3. Stock and Flow Diagram of Loading Fertilizer

Fig. 3. Stock and Flow Diagram of Loading Fertilizer

To run the distribution simulation, activities will be carried out in the system dynamics simulation. The activities in this simulation are divided into four activities. The first activity is loading from the PT. X warehouse to the ship using a conveyor. The second activity is that after the ship is fully loaded according to the specified payload, the ship will sail according to the distance and speed of the ship. The third activity is that after the ship arrives at its destination, the fertilizer will be unloaded by Shore Crane DC and will be carried by truck to the DC Medan warehouse.

Fig. 4. Stock and Flow Diagram of Logistic Costs

Fig. 4. Stock and Flow Diagram of Logistic Costs

To calculate the fuel requirements, there are 6 different ships whose fuel requirements will be calculated according to the specifications of the Main Engine and Auxiliary Engine of the ship. In this simulation, two ship conditions will be calculated, when sailing and unloading at the port. For fertilizer loading simulation, fertilizer will be moved from the PT. X warehouse using a conveyor or truck and crane to the selected ship until the ship's payload is full. For shipping, the ship will run according to the speed and distance that adjusts the real conditions of the ship and the berth distance so that the time can automatically adjust. For the flow of fertilizer, unloading using a shore crane and later it will be loaded in a truck so that the truck can move and distribute it to the DC warehouse. For Stock and Flow Diagrams this cost is the same model as the causal loop diagram which is the initial benchmark for running this simulation. In the Stock and Flow Diagram, the logistics costs are divided into several parts that indicate different cost aspects. Stock and Flow Diagram refers to the movement of the Stock and Flow Diagram distribution. These aspects include conveyor costs, which are loading costs, shore crane costs, and DC truck costs, which are unloading costs, ship costs which are FO and LO costs, as well as DC warehouse rental costs located in Medan.

The simulation was carried out for 5 years, and Table. 2 shows a summary of the total cost of fertilizer distribution results. In addition to simulating the flow process of distribution and estimating cost, this paper also simulated the deficit between supply and demand in each scenario. The result from simulation of deficit of supply and demand in each scenario was taken into consideration for selecting the most efficient scenario.

Table 2. Total Costs in All Scenarios

Scenario | Total Cost | Total Cost per Ton
Scenario 1 | Rp221,334,233,586 | Rp264,172
Scenario 2 | Rp205,929,357,116 | Rp245,786
Scenario 3 | Rp202,349,574,658 | Rp241,513
Scenario 4 | Rp231,082,903,420 | Rp275,808
Scenario 5 | Rp209,814,390,200 | Rp250,423
Scenario 6 | Rp200,088,981,642 | Rp238,815
Scenario 7 | Rp257,995,339,192 | Rp307,929
Scenario 8 | Rp242,517,850,297 | Rp289,456
Scenario 9 | Rp239,013,127,874 | Rp285,273
Scenario 10 | Rp267,748,292,343 | Rp319,569
Scenario 11 | Rp246,462,348,627 | Rp294,164
Scenario 12 | Rp236,743,605,977 | Rp282,564

Scenario 1 is a distribution model scenario using a conveyor when loading from PT. X and using a ship that has a payload of 16,800 tons. The total cost obtained from the simulation of scenario 1 for five years reached and per ton. The number of ship trips in scenario 1 reach 70 trips. In Figure 5a, there are 3 months in 2019 that are found to have a fertilizer difference, May, June, and July. In May the fertilizer data submitted was less than 16,513 tons of fertilizer from the existing demand. In June there was an excess of 3,225 tons of fertilizer and in July there was also an excess of 13,258 tons. This happened because the selected ship payload is relatively small.

Fig. 5. Deficit between Supply and Demand in a) Scenario 1; b) Scenario 2; c) Scenario 3; d) Scenario 4.

Fig. 5. Deficit between Supply and Demand in a) Scenario 1; b) Scenario 2; c) Scenario 3; d) Scenario 4.

Scenario 2 is a distribution model scenario using a conveyor when loading from PT. X and using a ship that has a payload of 26,100 tons of fertilizer. The total cost obtained from the simulation of scenario 2 for five years reached and per ton. The price is quite expensive because the payload is still relatively small and the number of ship trips in scenario 2 reached 52 trips. However, the higher payload, the lower the number of trips, so that the operational cost of ship can decrease. The number of trips is one of the important aspects of the total distribution price. In Figure 5b, there are 2 months in 2019 were found to have a fertilizer difference, June, and July. In June the fertilizer data submitted was less than 3,958 tons of fertilizer from the existing demand and in July there was an excess of 3,958 tons of fertilizer.

Scenario 3 is a distribution model scenario using a conveyor when loading from PT. X and using a ship that has a payload of 34,300 tons of fertilizer. The total cost obtained from the simulation of scenario 3 for five years reached and the price per ton reached . The price is relatively low because the large payload can carry more cargo, the more tonnage of fertilizer carried in one trip then the number of trips can be less. The number of ship trips in scenario 3 reached 48 trips. In Figure 5c, there is no fertilizer deficit resulting from this scenario. This is due to the fertilizer that is brought according to the amount of demand from each month that is available.

Scenario 4 is a distribution model scenario using a conveyor when loading from PT. X and using a ship that has a payload of 52,200 tons. The total cost obtained from the simulation of scenario 4 for five years reached Rp231,082,903,420 and Rp275,808 per ton. The number of ship trips in scenario 4 is 47 trips. In Figure 5d, there is no fertilizer deficit resulting from scenario 4. This happened because the supply of fertilizer carried by ship followed the monthly demand.

Fig. 6. Deficit between Supply and Demand in a) Scenario 5; b) Scenario 6; c) Scenario 7; d) Scenario 8.

Fig. 6. Deficit between Supply and Demand in a) Scenario 5; b) Scenario 6; c) Scenario 7; d) Scenario 8.

Scenario 5 is a distribution model scenario using a conveyor when loading from PT. X and using a ship that has a payload of 41,400 tons. The total cost obtained from the simulation of scenario 5 for five years reached and in price per ton, it reached . The number of ship trips in scenario 5 reached 48 trips. In Figure 6a above, there is no fertilizer deficit resulting from scenario 5. This happened because the supply of fertilizer carried by ship followed the monthly demand.

Scenario 6 is a distribution model scenario using a conveyor when loading from PT. X and using a ship that has a payload of 25,200 tons. The total cost obtained from the simulation of scenario 6 for
five years reached Rp200,088,981,642 and Rp238,815 per ton. The number of ship trips in scenario 6 reached 55 trips. In June 2019 the fertilizer data submitted was less than 4,858 tons of fertilizer from the existing demand. In July there was an excess of 4,858 tons of fertilizer, this is because the fertilizer deficit in June was distributed in the following month. The result can be seen in Figure 6b.

Scenario 7 is a distribution model scenario using trucks and cranes when loading from PT. X and using a ship that has a payload of 16,800 tons. The total cost obtained from the simulation of scenario 7 for five years reached Rp 257,995,339,192 and Rp307,929 per ton. The number of ship trips in this scenario reached 70 trips. In Figure 6c above, 3 months in 2019 were found to have a fertilizer difference, May, June, and July. In May the fertilizer data submitted was less than 16,513 tons of fertilizer from the existing demand. In June there was an excess of 3,225 tons of fertilizer and in July there was also an excess of 13,255 tons. This was because the fertilizer deficit in May was distributed in the following month.

Scenario 8 is a distribution model scenario using trucks and cranes when loading from PT. X and using a ship that has a payload of 26,100 tons of fertilizer. The total cost obtained from the simulation of scenario 8 for five years reached Rp242,517,850,297 and Rp289,456 per ton. The number of ship trips in this scenario reached 52 trips. In Figure 6d, 3 months in 2019 were found to have a fertilizer difference, May, June, and July. In May the fertilizer data submitted was less than 14,653 tons from the existing demand. In June there was an excess of 10,095 tons and in July there was an excess of 3,718 tons, this was because the fertilizer deficit in May was distributed in the following month.

Fig. 7. Deficit between Supply and Demand in a) Scenario 9; b) Scenario 10.

Fig. 7. Deficit between Supply and Demand in a) Scenario 9; b) Scenario 10.

Scenario 9 is a distribution model scenario using trucks and cranes when loading from PT. X and using a ship that has a payload of 34,300 tons. The total cost obtained from the simulation of scenario 9 for five years reached Rp239,013,127,874 and Rp285,273 per ton. In Figure 7a, there is no fertilizer deficit resulting from this scenario 9. This happened because the supply of fertilizer carried by ship followed the monthly demand.

Scenario 10 is a distribution model scenario using trucks and cranes when loading from PT. X to ship and using a ship that has a payload of 52,200 tons. The total cost obtained from the simulation of scenario 10 for five years reached and per ton. The number of ship trips reached 47 trips. In Figure 7b, no fertilizer deficit results from this scenario.

Fig. 8. Deficit between Supply and Demand in a) Scenario 11; b) Scenario 12.

Fig. 8. Deficit between Supply and Demand in a) Scenario 11; b) Scenario 12.

Scenario 11 is a distribution model scenario using trucks and cranes when loading from PT. X to ship and using a ship that has a payload of 41,400 tons. The total cost obtained from the simulation of scenario 11 for five years reached Rp246,462,348,627 and Rp294,164 per ton. In Figure 8a, two months in 2019 were found to have a fertilizer difference, May and June. In May the fertilizer data submitted was 433 tons less than the existing demand. In June there was an excess of 73 tons of fertilizer, this is because the fertilizer deficit in May was distributed in the following month.

Scenario 12 is a distribution model scenario using trucks and cranes when loading from PT. X to ship and using a ship that has a payload of 25,200 tons. The total cost obtained from the simulation of scenario 12 for five years reached and per ton. In Figure months in 2019 were found to have a fertilizer difference, May, June, and July. In May the fertilizer data submitted was less than 16,663 tons of fertilizer from the existing demand. In June there was an excess of 11,415 tons of fertilizer and in July there was an excess of 4,858 tons, this was because the fertilizer deficit in May was distributed in the following month.

There are two parameters to select the best scenario: scenario with the minimum total cost and a scenario with no deficit. From the simulation results above, it can be concluded that scenarios 3 and 6 have minimal distribution costs among all existing scenarios. However in the result of scenario 6 there is a deficit, so the selected scenario is scenario 3 . Scenario 3 has minimum cost because the payload on the ship was quite suitable for the demand and this factor also impacted the number of ship trips. The fewer number of ship trips resulted in decreasing fuel oil consumption of the ship. Selection of the right type of heavy equipment for loading and unloading cargo can impact in energy saving/fuel consumption and minimize operational costs.

Conclusion

The original version of this paper is available on https://www.scientific.net/EI.9.45.pdf

From the results of research carried out in the paper, the authors summarize as follows:

In providing alternative forms of scenarios, 12 scenarios have been created. The scenarios consist of loading cargo, ship payload, unloading cargo, and warehouse rental. For loading cargo, two aspects will be simulated, i.e., loading using a conveyor or loading using trucks and cranes. For ships, there are about 6 ships that have different payloads. The ship's payload varies from 16,800 tons to 52,200 tons and the warehouse rental cost with the provision of data obtained from the PT. X.

The twelve (12) scenarios were simulated in the Powersim Studio 8 software. From the simulation results, a comparison of each cost in each scenario is obtained and scenario 3 has the lowest distribution costs.

There is no deficit in the scenarios , and 10 because they have sufficient cargo to distribute fertilizer according to demand. Scenario 3 has the minimal distribution costs because the payload is quite large so that the number of ship trips are relatively small. Number of ship trips have a great influence on fuel oil consumption in one year. Scenario 3 is an alternative scenario that uses conveyors when loading, has a shipload of 34,300 . tons, as well as loading and unloading using shore cranes and trucks. The total logistics cost is Rp202,349,574,658, the cost per ton is Rp241,513 and there is no fertilizer deficit every month.

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The original version of this paper is available on https://www.scientific.net/EI.9.45.pdf

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Engineering Innovations, ISSN: 2813-1002, Vol. 9, pp 57-69

doi: 10.4028/p-hz1Qla

© 2024 The Author(s). Published by Trans Tech Publications Ltd, Switzerland.

Submitted:
2022-11-11

Revised:
2023-05-30

Accepted:
2023-06-06

Online:
2024-02-12

Business Model Design for Cathode Material Manufacturer Startup Case Study: PT Polimikro Berdikari Nusantara

The original version of this paper is available on https://www.scientific.net/EI.9.57.pdf

Dian Ahmad Pratama Bunayah Sudian , Wahyudi Sutopo and Muhammad Hisjam

¹Department of Industrial Engineering, Faculty of Engineering, Universitas Sebelas Maret

Centre of Excellence for Electrical Energy Storage Technology, Universitas Sebelas Maret

Research Group Industrial Engineering and Techno-Economic, Industrial Engineering, Universitas Sebelas Maret

dianahmad59@gmail.com, wahyudisutopo@staff.uns.ac.id, hisjam@staff.uns.ac.id

Introduction

The original version of this paper is available on https://www.scientific.net/EI.9.57.pdf

A startup is a new company with a business model based on innovation and technology [1]. Startup companies offer innovation as the main value. While they usually offer high scalability, they also have a high-risk failure during commercialization and fall into the valley of death [2]. To survive startup should have a business strategy to stand out in the crowd based on its capabilities [3]. For example, Tesla comes into the market as a high-end electric vehicle car, drawing the attention of highincome people to buy the product. Meanwhile, Rivian as an electric vehicle company come to market. As a company that relies on innovation and technology as selling points, startups need to pay attention to their Technology Readiness Level (TRL) and Market Readiness Level (MRL). TRL and MRL are defined as a method for evaluating a product's readiness for market. TRL measures the readiness or maturity of the technology developed in its products, while MRL measures the readiness of technology commercialization to the market [4]. TRL and MRL are necessary to identify because "no market need" is the second greatest reason why startups fail [5], with a failure percentage of , the percentage comparison is quite thin with the first rank, which is "run out of cash or failed to raise new capital" with rate of failure. To increase TRL, a startup needs product development. Meanwhile, to increase MR, startup needs a good business model.

This research takes a case study at the startup Polimikro Berdikari Nusantara (PBN), a lithium-ion battery cathode material manufacturer company. From the observation, PBN is at TRL 7 Demonstration System. PBN products have passed TRL level 6 because they have passed the specified standard tests, and test results can be seen in the product catalog. There has been a transaction on a laboratory production scale by a startup named Lectro to conduct research, and repeat orders have been made to conclude that the product has been demonstrated in the lab environment and is successful. To enter TRL 8, the test is still not enough to meet "Qualified" because the quantity is still very small, and there is no procedure for identifying product problems in trials in the actual ecosystem. Meanwhile, based on observation, PBN is at MRL 4 Small Scale Early Adopter Campaign. The first reason is that PBN has made sales transactions and has an early adopter, so the

Minimum Viable Product (MVP) has been validated to work well. PBN has explained its products in a pitch deck that can provide an overview of the company's product concept. The second reason is that PBN has customers but has yet to reach at least 50 transactions. There has been no massive marketing considering the production capacity. Current customers are startups that are early adopters and only one company, so currently, PBN is still at MRL 4. At least it requires a minimum of 100 successful transactions to reach MRL 5.

The market for PBN can also be seen on the National Battery Research Institute (NBRI) website. NBRI is an independent Indonesian institution for electrochemical energy storage science and technology, supporting research, training, and education [6]. NBRI has 659 individual members, 62 institutional members, and 28 corporate members. This member of the NBRI can be a potential target market for PBN. Several business strategies need to be made to increase PBN's MRL to reach the existing target market. There are various ways to project a business strategy through a business model, and one that startups often use is the Business Model Canvas (BMC) by Osterwalder & Pigneur. Business Model Canvas (BMC) is a design model prepared to quickly present the company's conditions, capabilities, and targets in running its business [7]. Besides BMC, startups often use the business model framework Lean Canvas (LC) by Ash Maurya, with a lean principle. The lean principle can be described as a way for the company to release a product or service with limited capital as soon as possible [8]. Ash Maurya believes that BMC is suitable for large companies focusing on improving technology and innovation. However, it is still less efficient for newly formed companies and is still focused on validating and developing ideas for commercialization, so he developed BMC and proposed a business model framework called Lean Canvas (LC) [9]. BMC is focused on existing companies that want to innovate while LC is focused on new companies or companies that want to make radical innovations [10]. Unlike other business plans, lean startups do not focus on making perfect plans but rather implement learning by doing with improvements obtained from consumer feedback to get products or services that are ideal and needed by consumers [11]. Several previous researchers have integrated several business model frameworks to build the most suitable business model for the company, for example, BMC and SWOT (Strength, Weakness, Opportunity, Threat) [12], [13], BMC and BOS (Blue Ocean Strategy) [14], BMC and LC [15]. In the paper [15] researcher conduct interview without data validation, and choose one business model framework considered the best. In this paper, BMC and LC will be used simultaneously using interactive analysis and triangulation data validation. LC can be used when the company or startup does not have a mature product and market and is still at the idea validation stage, while BMC can be used when the company is mature enough but still wants to continue to develop through its technology and innovation.

Data Analysis Method

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This study uses an interactive analysis model by Miles and Huberman [16] to perform data analysis. The previous researcher applied the interactive analysis model to determine the implementation of business strategy [17]. It was chosen because it is suitable for the business strategy that the researcher wants to design because of the interactive and continuous nature of the research. Moreover, if there still needs to be more data, the researcher can collect data again [18]. The interactive analysis model is one of the data analysis techniques in qualitative research. The interactive analysis model has four analysis components: data condensation, data display, and data verification. This process is carried out by a data collection process where the four components interact with each other. The interaction can be seen in the Figure 1 below. After the data has been obtained, the researcher can display the data directly. Examples of data that can be used are photos and observation notes, but if the data is too large, such as interview transcripts or company documents, the researcher condenses the data to make it easier to understand. One of the data condensation techniques that can be used is coding. After the data is successfully displayed and condensed, the next step is data verification or data drawing. If the data is valid then the data search is complete, if the data is not valid then the data search, data display and data condensation can be carried out again.

Fig. 1. Interactive Analysis Model

Fig. 1. Interactive Analysis Model

Data Collection

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This research uses a qualitative research approach. Qualitative research has four procedures: literature study, interview, observation, and documentation [19]. To carry out business strategy planning at Polimikro Berdikari Nusantara (PBN), this study used three procedures: observation, interviews, and documentation for data collection. Data collection in this study was carried out in the period August 2021 - June 2022.

1. Observation

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Observation is a data collection technique where researchers go to the field to observe everything related to space, place, actors, activities, objects, time, events, goals, and feelings. In this study, researchers made observations on the production floor and chatted with members of the company's directors to find facts that occurred in the field. Observations in this study aim to see the current conditions and test the data's validity to increase the research's credibility. The object of research observation can be seen in the Table 1, represent production site and distribution channel where the data collected.

Table 1. Observation Object

No. | Object
1 | Production Floor PBN
2 | Office PBN
3 | Website polimikroid.com
4 | Tokopedia PolimikroOfficial
5 | Instagram @polimikroberdikarimusantara

2. Documentation

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In this study, the researcher collected qualitative data by viewing and analyzing the documents made by the research subjects. Documentation aims to obtain information that can be used as an addition or validation to the information obtained through two other methods: interviews and observation. Documentation is also useful for testing the validity of the data to increase the credibility of the research. The documents used in this study can be seen in the Table 2 represent all the documents owned by PBN during research.

Table 2. Documentation Object

No. | Object
1 | Operation Process Chart (OPC)
2 | Sales Report
3 | X-Ray Diffraction (XRD) test result
4 | Scanning Electron Microscope (SEM) test result
5 | Pitch Deck PBN

3. Interview

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An interview is a data collection technique that involves verbal communication between researchers and research subjects [20]. Interviews were conducted using a semi-structured interview method. Semi-structured interviews or semi-structured interviews are interviews that involve open-
ended questions or open answers but are still on the topic area that the researcher wants to study. Researchers and research subjects can discuss a topic further to get more detailed information. Researchers can develop questions based on answers from subjects to previous questions. To validate data, informants are divided into three types: key informants, main informants and supporting informants. Key informants are informants who have various basic research information. The main informants are informants who are directly involved with the research topic. Supporting informants provide additional information that can complement researchers [21]. The subjects interviewed can be seen in the Table 3 below.

Table 3. Informants

No | Object | Position | Source Type
1 | Muhammad Nur Ikhsanudin, S.T. | Chief Executive Officer | Key Informant
2 | Mintarsih Rahmawati, S.T, M.T. | Chief Technology Officer | Main Informant
3 | Shofirul Sholikhatun Nisa, S.T., M.T. | Chief Marketing Officer | Main Informant
4 | Meidiana Arinawati, A.Md. | Chief Data Officer | Main Informant
5 | Yulaikha Ariyani, A.Md | PUI-PT Electrical Energy Storage Technology UNS | Supporting Informant
6 | Yazid Rijal Azinuddin, A.Md.T | Customer | Supporting Informant
7 | Khikmah Nur Rikhy Stulasti, S.T. | Customer | Supporting Informant

Data Condensation

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Data condensation is carried out to obtain clearly described data under the main idea and research theme. Data condensation can be interpreted as summarizing the important research points to find patterns. In this study, condensation is needed to interpret the results of interviews through the coding method. The data condensation carried out in this study was by coding each block containing questions. Furthermore, the answers of the informants in each block are summarized by referring to the BMC and LC frameworks in the Table 4. Apart from blocks from LC and BMC, each informant was also given a code to identify the source during the coding process of the interview results.

Table 4. Block Code

Code | Description
PT | Pertanyaan Tambahan (Additional Question)
U | Urutan (Order)
CS | Customer Segments
VP | Value Proposition
CH | Channels
CR | Customer Relationships
RS | Revenue Streams
KR | Key Resources
KA | Key Activities
KP | Key Partners
COS | Cost Structure
EA | Early adopters
P | Problems
S | Solutions
EXA | Existing Alternatives
HLC | High-Level Concept
KM | Key Metrics
IK | Muhammad Nur Ikhsanudin, S.T.
SH | Shofirul Sholikhatun Nisa, S.T. M.T.
MN | Mintarsih Rahmawati, S.T., M.T.
ME | Meidiana Arinawati, A.Md
YU | Yulaikha Ariyani, A.Md.
YZ | Yazid Rijal Azinuddin, A.Md.T.
KH | Khikmah Nur Rikhy Stulasti, S.T.

Data Display

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The data that has been condensed is grouped with a certain pattern and then translated according to the pattern determined by the researcher. The data display carried out in this study was presented in the form of paragraphs, tables, graphics, and supplementary data as voice based on the research object from Table 1, Table 2, and Table 3. The list of data displays can be seen in the Table 5.

Table 5. Data Display

No | Data Type | Data Collection | Data Display
1 | Observation | Company Profile and History | Paragraph, Table, and Graphic
Founder's background | Paragraph
Intellectual property | Paragraph and Graphic
Product list | Table
Company's channels | Paragraph
2 | Documentation | Company's sales report | Table
Bill of Materials | Graphic
Operation Process Chart | Graphic
Product performance, efficiency, and capacity | Graphic
Product specs and test result | Graphic
3 | Interview | Interview recording | Voice
Interview transcript | Table

Data Verification

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There are four data validity tests, namely the credibility test, dependability test, transferability test, and confirmability test [22]. This study uses a credibility test to validate the data so that the data obtained is credible and can be accounted for. Six techniques can be used to test the credibility of the data, namely triangulation, observation extension, increasing persistence, negative case analysis, member check, and reference materials. This research uses the triangulation technique to test the credibility of the data. There are three triangulation techniques, namely source triangulation, technical triangulation, and time triangulation. This research uses the source triangulation technique and technique triangulation. These techniques were considered because the data were collected from various sources and techniques. Source triangulation was carried out based on three research subjects: key informants, main informants, and supporting informants Meanwhile, technical triangulation is carried out based on three data collection techniques: interviews, observation, and documentation. The component of the triangulation can be seen in the Figure 2. Researcher conduct observation, documentation, and interview to collect data. The results of the three different data collection techniques were compared to validate one another, if the researcher finds contradictions from the comparison of data, then data retrieval is carried out to clarify the actual data. Furthermore, the results of interviews with different sources, namely from key informant, main informants and supporting informants were compared.

Fig. 2. Triangulation

Fig. 2. Triangulation

Result

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Data collection through observation, documentation, and interviews has been carried out. The data obtained is condensed and displayed in the form of paragraphs, tables, and graphs. Furthermore, the data is verified by triangulation technique and poured in the form of BMC and LC framework to represent the commercialization strategy.

1. Business Model Canvas (BMC)

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1.1 Customer Segment

In this block, the type of customer segment PBN focuses on is the niche market, namely researchers in the field of lithium-ion batteries and battery manufacturing companies with the main focus on selling advanced materials. However, by listing products on Tokopedia, PBN implements a marketing strategy for the mass market because it only does listings and does not carry out marketing strategies that focus on researchers. It is planned that PBN will send emails to lecturers who focus on lithiumion batteries, but this still needs to be implemented. As for manufacturing batteries, PBN has not yet made an official offer to many manufactured batteries in Indonesia, only Batex, because they are in the same building. Batex accepts the offer of cooperation, but there is no official agreement that regulates it.

1.2 Value Proposition

PBN has 2 product categories that are sold, namely advanced and functional materials. Advanced materials are produced by PBN themselves, while functional materials are not, PBN acts as a reseller. The value that PBN wants to offer is a cheaper price because it eliminates shipping costs between countries and import taxes. In addition, because it is a domestic product, the advanced material produced by PBN can increase the Domestic Content Level (TKDN) required by lithium-ion battery manufacturing companies. As for researchers, PBN prioritizes the speed and ease of purchasing through the marketplace

1.3 Channel

PBN has six channels for distributing products and communicating with consumers. The channels in question are the polimikroid.com website, Tokopedia PolimikroOfficial, Instagram @polimikroberdikarinusantara, Whatsapp Business, Email polimikroberdikarinusantara@gmail.com, and the office at the UNS Pusbangnis Building, 1st floor.

1.4 Customer Relationship

Currently, PBN interacts with consumers through chat held by PBN members. However, chat is not automatic and is answered directly by personal (personal assistance) for consumers to ask questions and consult. In addition, PBN also relies on the Tokopedia marketplace to provide complete product listings that consumers can purchase independently without even contacting PBN (self-service).

1.5 Revenue Streams

PBN relies on product sales or asset sales as a source of income. Consulting services are currently consumer services and are not subject to tariffs, so they do not provide revenue. As for the patent, is owned by UNS so PBN cannot license the patent for production without UNS' approval. Even when the patent is ready, PBN must pay UNS's license fee. Some PBN members consider the investment as income, but it is an addition to capital and cannot be distributed as dividends, so it is not a revenue stream. PBN has three payment mechanism options: preorder, direct purchase, and negotiation. Preorders for advanced material products, direct purchases for functional material products, negotiations for purchases above 5 kg , and custom materials.

1.6 Key Resources

The main resources needed by PBN are production equipment (physical) owned by PUI-PT Electrical Energy Storage Technology UNS which is currently still free of charge because PBN is a manufacturing startup that does production. In addition, PBN requires experts who understand advanced and functional materials because only some have this knowledge. Another important resource is PBN's (intellectual) patents to differentiate itself from competitors.

1.7 Key Activities

As a manufacturing company, PBN's main activity is production. However, in addition to production, PBN also promotes its products because currently, sales of advanced materials are still far from production capacity, so promotion is still needed. In contrast, PBN is a reseller of functional materials, so its main activity is marketing. In addition, PBN is also developing new methods to improve the quality of its products because, currently, it still needs to catch up to Chinese companies.

1.8 Key Partners

PBN cooperates with PUI-PT Electrical Energy Storage Technology UNS and Batex to improve efficiency or Optimization and Economy of Scale. As a result, PBN and PUI-PT Electrical Energy Storage Technology UNS establish a mutually beneficial relationship, PBN does not need to purchase expensive material production equipment, and PUI PBN acts as a startup at the forefront of the commercialization of PUI technology. Meanwhile, Batex PBN acts as a supplier for making batteries that can increase the Domestic Content Level (TKDN).

1.9 Key Activities

Cost components that need to be considered by PBN are materials procurement for production and reselling, inventory cost for materials stock, equipment and office rental for business activity, marketing costs to promote the product, licensing fees for UNS patents, and salaries for experts. Identified costs are costs that are required in the current business can run.

2. Lean Canvas (LC)

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Lean Canvas (LC) is a business model framework proposed by Ash Maurya [23] with the same purpose as Business Model Canvas (BMC), a single canvas that can describe business activities. Ash Maurya modified several blocks to fit the business model by adopting lean principles. The explanation of each block based on the data obtained is as follows:

2.1 Early Adopters

In this block, business people create a list of customers they feel are ideal to pay attention to and serve to get input. Customers who are used as early adopters are customers who place orders at the beginning of the establishment of a business and communicate intensely to get input on the products offered. Early adopters of PBN are Batex and Lectro researchers. Batex is an energy startup that sells lithium-ion batteries and their derivatives. Batex has built a partnership with PBN to increase TKDN in its products. Lectro chooses PBN's product because of its faster delivery and easier to access than alternatives.

2.2 Unique Value Proposition

This block emphasizes that startups have a differentiator from the alternatives already on the market. However, the existing differences must have advantages that can attract the attention of target consumers. In this block, PBN offers advantages foreign producers will find difficult to imitate, namely the increase in TKDN content. In addition, domestic production carried out by PBN can save shipping costs and delivery speed for the Indonesian market.

2.3 Unfair Advantage

There are two advantages of PBN that current competitors cannot easily imitate. The first is a simple patent entitled "Method of Making Lithium Nickel Cobalt Manganese Oxide Rich Nickel Cathode Material". The second is the production domicile in Indonesia to increase the Domestic Content Level (TKDN) for manufacturing companies that order PBN materials.

2.4 High-Level Concept

During the interview, PBN identified several companies for review, including Targray, NEI Corporation, and Gelon. At the time of documentation, the researcher found that Gelon is a company that can produce NMC, LFP, and NCA in China with product prices that are more expensive than in Indonesia and relatively long delivery (1-3 months). From this, it is concluded that the high-level concept of PBN is like Gelon with cheaper product prices with faster delivery and can increase TKDN.

2.5 Existing Alternatives

The alternative for purchasing advanced materials at this time is through distributors who make purchases from abroad, or some consumers buy products directly by importing. However, current alternatives present difficulties in the form of long delivery times and additional shipping and import taxes costs.

2.6 Problems

The problem that PBN has identified and wants to solve is the difficulty in purchasing materials for Indonesian consumers. The main seller of advanced materials is China, so consumers make purchases through distributors, or import directly. This causes large shipping costs and long waiting times, besides the aftersales offered need to be more satisfactory.

2.7 Solutions

To answer the identified problems, PBN offers several facilities that are features of its business model. The first is to do their production in the country. With the presence of PBN as a local producer, the price of shipping costs and delivery times can be cut. In addition, PBN provides free consultation as a consumer after-sales service.

2.8 Key Metrics

To provide competitive prices, PBN should consider the possible production cost. PBN can use lead time delivery as an evaluation benchmark for fast delivery times. In addition, to measure success in marketing, PBN can measure the number of new purchases (new orders) and repeat purchases (repeat orders). PBN sees reviews as a benchmark for overall performance to measure consumer satisfaction. As for product development, PBN can use the results of capacity and efficiency performance tests.

3. Business Model Canvas (BMC) and Lean Canvas (LC) Integration

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After identifying each block on the Business Model Canvas (BMC) and Lean Canvas (LC), the author puts it on one canvas sheet representing a business model that is easy to understand. Each block canvas arranged by considering business process. First, company define problem occurred and determine solution that can be offered to solve the problem. Next, the company establish a business model by determining the target market that has problems identified by the company. Furthermore, the company determines what value is offered as a solution to turn the problem into a business opportunity that is difficult for competitors to imitate on a unique value proposition block. Then the company determines how to deliver that value to customers in the channel block, and how to establish communication in the customer relationship block. After that, the company determines how revenue is obtained from the value offered in the revenue stream block. Furthermore, on the product side, the company determines the resources in key resource block and activities in key activities block that needed to create the value that the company wants to offer as a solution to the problem. If there are resources or activities that cannot be carried out but are really needed by the company, then the company must identify partners in the block key partners so that value can be created. Finally, in the process of establishing a business model, the company determines what costs are needed by the company. The final stage is the process of evaluating and measuring ideas, in which the company determines ideal customers that can be surveyed and provides input in creating value in the early adopter block. This value is compared to current solutions offered by competitors in the existing alternatives block. The uniqueness that is obtained is expressed by a simple analogy to the high-level concept block so that it is as easy as possible to understand. Furthermore, the company determines key performance indicators in the key metrics block based on company activities and goals. Furthermore, the company determines key performance indicators in the key metrics block based on company activities and goals. Finally, as the business continues, the company can determine advantages that cannot be copied by competitors in the unfair advantage block, so that the company can dominate the market in business competition. BMC and LC Integration framework can be seen in Figure 3, while the results of this study on PBN can be seen in figure 4.

Fig. 3. BMC and LC Integration Framework

Fig. 4. Business Model

Fig. 4. Business Model

Summary

The original version of this paper is available on https://www.scientific.net/EI.9.57.pdf

The interactive analysis model was successful in creating a business model commercialization strategy. The business model framework used is Business Model Canvas (BMC) and Lean Canvas (LC). Conclusions were obtained that answered the formulation of the research problem and fulfilled the research objectives as follows:

The Interactive Analysis Model has been successfully used to develop a business model based on the Business Model Canvas (BMC) and Lean Canvas (LC) frameworks.

The value offered by PBN is material that is produced domestically which can provide a lower price, easy access, and faster delivery because it can eliminate shipping problems, besides that domestic production provides unfair advantages in being able to offer an increase in TKDN for battery manufacturing companies and PBN own intellectual property on one method of making the material.

In reaching target consumers, namely researchers and battery manufacturers, PBN distributes its products through the Tokopedia marketplace, which can be purchased directly at the office. Meanwhile, PBN utilizes Whatsapp Business, Tokopedia, Instagram, Email, website, and direct interaction in the office to connect and provide customer service.

PBN's main partners are PUI-PT Electrical Energy Storage Technology as a provider of equipment, Batex as a prospective company to be supplied by PBN, and Pertamina as an incubator, while the main activities of PBN are production, marketing, and product development with the main resources namely production tools, experts and intellectual property. Alternative solutions to current consumer problems are buying directly from distributors or importing. However, this causes several problems, such as difficulty in purchasing, expensive shipping costs, long waiting times, and minimal aftersales. Therefore, PBN presents solutions through an easy purchasing process, fast delivery, and after-sales service in free consultations.

Acknowledgment

The original version of this paper is available on https://www.scientific.net/EI.9.57.pdf

This research was supported by the UNS LPPM Research Scheme, Contract No: 2277.1/UN27.22/PT.01.03/2022; July 29, 2022- COLLABORATIVE RESEARCH PROGRAM FOR DOMESTIC HIGHER COLLABORATIONS (PKPTDN)

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Keywords Index

A

Annealing Influence of Annealing Duration on the Structural, Optical and Electrical Properties of ZnO Layers Deposited Using the Dip-Coating Method

Automatic Aiming Design and Implementation of Automatic Aiming and Locking System

Automatic Locking Design and Implementation of Automatic Aiming and Locking System

C

Cascading Classifier Design and Implementation of Automatic Aiming and Locking System

D

Dip Coating Influence of Annealing Duration on the Structural, Optical and Electrical Properties of ZnO Layers Deposited Using the Dip-Coating Method

E

Efficiency Cost System Dynamics Model to Improve Logistics Cost Efficiency in Fertilizer Distribution Outside Java (Gresik - Medan)

Electrocatalyst; Oxygen Evolution Reaction; Cathodization Cathodized Stainless Steel Mesh for Binder-Free Layer Double Hydroxides Oxygen Evolution Reaction Electrode

F

Face Recognition Design and Implementation of Automatic Aiming and Locking System

Fertilizer System Dynamics Model to Improve Logistics Cost Efficiency in Fertilizer Distribution Outside Java (Gresik - Medan)

L

Logistic System Dynamics Model to Improve Logistics Cost Efficiency in Fertilizer Distribution Outside Java (Gresik - Medan)

O

Opencv Design and Implementation of Automatic Aiming and Locking System

R

Reactive Power Compensation; Capacitors; Radial Distribution Network; Compensator Placement; Optimal Position Optimal Location of Capacitor in a Radial Distribution System Using New Hybrid Method

Rechargeable Aqueous Zinc-ion Batteries; Zinc Anode; Polyacrylonitrile Use of Polyacrylonitrile as Anodic Artificial Solid Electrolyte Interphase for Aqueous-Based Zinc-Ion Batteries

Robot Arm Design and Implementation of Automatic Aiming and Locking System

S

System Dynamics System Dynamics Model to Improve Logistics Cost Efficiency in Fertilizer Distribution Outside Java (Gresik - Medan)

Z

Zno Layers Influence of Annealing Duration on the Structural, Optical and Electrical Properties of ZnO Layers Deposited Using the Dip-Coating Method

Authors Index

A

Aprilia, P. System Dynamics Model to Improve Logistics Cost Efficiency in Fertilizer Distribution Outside Java (Gresik - Medan)

Artana, K. System Dynamics Model to Improve Logistics Cost Efficiency in Fertilizer Distribution Outside Java (Gresik - Medan)

C

Chen, P. Design and Implementation of Automatic Aiming and Locking System

F

Fifatin, F. Optimal Location of Capacitor in a Radial Distribution System Using New Hybrid Method

G

Gonda, M. Optimal Location of Capacitor in a Radial Distribution System Using New Hybrid Method

H

Handani, D. System Dynamics Model to Improve Logistics Cost Efficiency in Fertilizer Distribution Outside Java (Gresik - Medan)

Hisjam, M. Business Model Design for Cathode Material Manufacturer Startup Case Study: PT Polimikro Berdikari Nusantara

I

Ibrahim, H. Optimal Location of Capacitor in a Radial Distribution System Using New Hybrid Method

K

Katon, Y. System Dynamics Model to Improve Logistics Cost Efficiency in Fertilizer Distribution Outside Java (Gresik - Medan)

Kheawhom, S. Use of Polyacrylonitrile as Anodic Artificial Solid Electrolyte Interphase for Aqueous-Based Zinc-Ion Batteries; Cathodized Stainless Steel Mesh for Binder-Free Layer Double Hydroxides Oxygen Evolution Reaction Electrode

L

Lumirang, M. System Dynamics Model to Improve Logistics Cost Efficiency in Fertilizer Distribution Outside Java (Gresik - Medan)

M

Matsuda, A. Influence of Annealing Duration on the Structural, Optical and Electrical Properties of ZnO Layers Deposited Using the Dip-Coating Method

Muangplod, N. Use of Polyacrylonitrile as Anodic Artificial Solid Electrolyte Interphase for Aqueous-Based Zinc-Ion Batteries

O

Oloulade, A. Optimal Location of Capacitor in a Radial Distribution System Using New Hybrid Method

P

Pan, C. Design and Implementation of Automatic Aiming and Locking System

Pung, S. Influence of Annealing Duration on the Structural, Optical and Electrical Properties of ZnO Layers Deposited Using the Dip-Coating Method

S

Somwangthanaroj, A. Use of Polyacrylonitrile as Anodic Artificial Solid Electrolyte Interphase for Aqueous-Based Zinc-Ion Batteries

Sripallawit, N. Cathodized Stainless Steel Mesh for Binder-Free Layer Double Hydroxides Oxygen Evolution Reaction Electrode

Sudian, D. Business Model Design for Cathode Material Manufacturer Startup Case Study: PT Polimikro Berdikari Nusantara

Sutopo, W. Business Model Design for Cathode Material Manufacturer Startup Case Study: PT Polimikro Berdikari Nusantara

T

Toe, M. Influence of Annealing Duration on the Structural, Optical and Electrical Properties of ZnO Layers Deposited Using the Dip-Coating Method

Y

Yaacob, K. Influence of Annealing Duration on the Structural, Optical and Electrical Properties of ZnO Layers Deposited Using the Dip-Coating Method