Papers by Keyword: Cathode

Abstract: The storage of electrical energy is an important thing today because it is influenced by the increasing human energy needs. Batteries are one of the energy storage that continues to be explored. Sodium-ion batteries are batteries that are planned to replace lithium-ion batteries. The abundance of sodium elements and their more economical price than lithium are the main attractions. The main constituent components of sodium batteries are anodes and cathodes. Both have a significant influence on the performance of sodium batteries. Currently, several cathodes have been developed but have some challenges especially their instability to air exposure. NaNi_0.5Ti_0.5O₂ is a transition metal oxide-based cathode that has been known to have good structural stability. In this study, NaNi_0.5Ti_0.5O₂ has successfully developed using a combination method of co-precipitation and solid-state. The precipitant is oxalic acid, while the chelating agent is ammonia. The obtained oxalate precursor was sintered in the airstream. Characterization of NaNi_0.5Ti_0.5O₂ is carried out. XRD patterns demonstrate a hexagonal-layered material structure. The material was achieved after the sintering process, according to FTIR analysis. XRF analysis confirmed the composition of the final product in the form of Ni 54.7% and Ti 45.26%. The SEM test showed uniform particles with an average size of 3 microns. Small particle size, which allows greater diffusion of Na ions thereby improving electrochemical performance. This structure characterization result shown that the used method has been succeed. The obtained EIS graph is a semi-circle and slope that shows the process of charge transfer of lithium ions on the surface of the material and electrolyte.

Abstract: A high-quality Lithium Nickel Manganese Oxide (LiNi_0.7Mn_0.3O₂) material is successfully synthesized via co-precipitation. The precursors for lithium rechargeable batteries have been prepared using starting materials (NiCl₂.6H₂O and MnSO₄.H₂O) with precipitating agents of oxalic acid and sodium hydroxide, Ethylene diamine tetra acetic (EDTA) and sodium hydroxide, and sodium carbonate for oxalate co-precipitation, hydroxide co-precipitation, and carbonate co-precipitation, respectively. Then, the precursors were calcined at 500°C for 5 hours, mixed with Li₂CO₃, and sintered at 850°C for 15 hours under oxygen. X-ray Diffraction (XRD) analysis results show that the particles obtained by oxalate co-precipitation (LiNi_0.7Mn_0.3O₂-C₂O₄) have higher crystallinity and more uniform particle shape than hydroxide co-precipitation and carbonate co-precipitation. The Fourier Transform Infrared (FTIR) spectroscopy characterization shows no carbonate group peak in the LiNi_0.7Mn_0.3O₂-C₂O₄. Furthermore, electrochemical tests were analyzed by evaluating the charge/discharge curves and cycling performance. The highest specific discharge capacity of 122 mAh/g was achieved by the LiNi_0.7Mn_0.3O₂-C₂O₄ sample, which also had a low capacity loss (22.7%), retaining 89.9% of its initial specific capacity at 0.5C between 2.5 and 4.25 V after 45 cycles. Based on these results, a cheap cobalt-free cathode material is promising for a new commercialized Li-ion battery.

Abstract: Lithium metal oxide such as NMC and NCA have been widely commercialized as electric vehicles. However, the cobalt content in the material is harmful to the environment, toxic, and expensive. This research aims to create a cathode material with a lower cost, efficient, and eco-friendly by extracting aluminum from the beverage cans waste as a cation-doping on the substitution of nickel material elements to repair material stability and electrochemistry performance. This study synthesized LNO cathode material by a solid-state method because it is low production cost and easy to synthesize. The extraction of beverage can waste successfully synthesized into alumina compounds corresponding to JCPDS card No. 29-0063. LNO cathode materials were prepared with a stoichiometric composition variation of LNO-P, LNO-Al 0.03, LNO-Al 0.07, and LNO-Al 0.1. Materials that have been successfully synthesized will be tested by X-Ray Diffraction to indicate that the material has a layered-hexagonal structure with high degree ordering. Fourier Transformed Infrared Spectroscopy tests to determine the composition of functional groups on LNO materials. The Scanning Electron Microscope analyzes the shape and morphology of surface material particles. Electrochemical testing uses cylinder batteries with a current of 0.1 C (1 C = 200 mA g-1) and a voltage of 2.6-4.3 volts, where obtained batteries LNO-P, LNO-Al 0.03, LNO-Al 0.07, and LNO-Al 0.1 with discharge capacity of 4.22 mAh g^-1, 31.82 mAh g^-1, 36.67 mAh g^-1, and 37.48 mAh g^-1

Abstract: Sustainable green new and renewable energy is continuously developed along with the development of cheap and commercially available secondary energy storage such as Li-ion batteries (LIBs). Nickel-rich cathode material obtained from cheap raw materials can significantly reduce the overall LIBs production cost and improve the overall process feasibility. For the first time, Ni-rich cathode material precursor was synthesized from mixed hydroxide precipitate (MHP). Based on MHP characterization test, the nickel content is high but have slight Mn and Mg level. NCM precursors was prepared in three facile steps, i.e., acid leaching using cheap and environmentally friendly organic acids, coprecipitation using oxalic acid, and thermal decomposition of as-prepared oxalate precipitate. Based on FTIR and XRD analysis, high crystalline oxalate dihydrate precipitates were successfully obtained. The morphological feature of the precipitate is significantly affected by the type of leaching solution. Fine metal oxides precursor powders also were successfully prepared which is confirmed by XRD, FTIR, and SEM analysis and can be readily used for Ni-rich cathode material preparation. In this study, NCM-Ox-LA have the best characteristic properties.

Abstract: With the development of new energy vehicles, it is necessary to develope new fast charging cathode materials for lithium ion batteries. This paper reports a simple carbon thermal reduction routine to synthesize layered LiMoO₂ cathode for Li-ion batteries. Impurity-free micro-crystalline powders were synthesized by one-step method with a thermal treatment at 800^°C for 5 hrs under N₂ atmosphere. The structural, morphological and electrochemical properties of LiMoO₂ were characterized by using X-ray diffraction pattern (XRD), scanning electronic microscopy (SEM), charge/discharge cycling and electrochemical impedance spectroscopy (EIS). The diffraction results indicate that the prepared sample has a layered hexagonal structure related to α-NaFeO₂. The secondary particles are in order of 2.0 μm length on average with homogeneous distribution. The initial discharge capacity of LiMoO₂ is 110.9 mAh·g^-1 at 0.1 C, and the capacity can still remain 92.8 mAh·g^-1 after 100 cycles. The good cycling performance and high rate discharge performance are attributed to the smaller charge-transfer resistance revealed by EIS results.

Abstract: The technology of applying the composite chrome-carbon coating to protect the conductive cathode pins in the aluminum industry is developed in this paper. The coating is based on the ability of fine-dispersed particles with size less than 0.5 micron.

Abstract: Li-ion batteries are one of the most popular energy storage devices widely applied to various kinds of equipment, such as mobile phones, medical and military equipment, etc. Therefore, due to its numerous advantages, especially on the NMC type, there is a predictable yearly increase in Li-ion batteries' demand. However, even though it is rechargeable, Li-ion batteries also have a usage time limit, thereby increasing the amount of waste disposed of in the environment. Therefore, this study aims to determine the optimum conditions and the potential and challenges from the waste Li-ion battery recycling process, which consists of pretreatment, metal extraction, and product preparation. Data were obtained by studying the literature related to Li-ion battery waste's recycling process, which was then compiled into a review. The results showed that the most optimum recycling process of Li-ion batteries consists of metal extraction by a leaching process that utilizes H₂SO₄ and H₂O₂ as leaching and reducing agents, respectively. Furthermore, it was proceeding with the manufacturing of a new Li-ion battery.

Abstract: This study shows the effectiveness of titanium dioxide (TiO₂) on a floating microbial fuel cell (FMFC). In the experiment, when a UV cutoff filter attached halogen lamp was used, the power density of the FMFC using pristine TiO₂ (P25) and the FMFC using TiO₂ sintered at 650 °C were was 2.11mW/m² and 10.44 mW/m² respectively. Next, when measured without UV cutoff filter, pristine TiO₂ type FMFC and 650°C sintered TiO₂ type FMFC recorded 2.93 mW/m² and 11.93 mW/m² respectively. From this result, it was confirmed that the power density was improved up to five times when the UV cutoff filter was used and four times when it was not used. According to the results of X-ray Diffraction (XRD), 650°C sintered TiO₂ is composed of more rutile phase than pristine TiO₂.

Abstract: Synthesis of LiFe_1-xGd_xPO₄/C with (x = 0.01; 0.05; 0.07) have been carried out using a solid-state method from LiH₂PO₄, Fe₂O₃, Gd₂O₃, and Carbon. Al reactant are mixed and mashed with a ball milling for 8 hours, then heated at 80°C for 2 hours to evaporate free water. To complete the reaction, the sample then was sintered at two different temperature; first at 350°C for 6 hours and continue at 830°C for 10 hours under Argon gas (Ar) atmosphere. The sintered powder was characterized by XRD to determine the structure and phase purity. Sample LiFe_1-xGd_xPO₄/C (x = 0.01; 0.05; 0.07) was adopted orthorhombic crystal structure and pnma space group, and no impurities detected. In general, the lattice parameter decreases with increasing Fe concentration, because of the size of the Fe³⁺ ion is smaller than that Gd³⁺ ion. Conductivities of LiFe_0.93xGd_0.07PO₄/C, LiFe_0.95Gd_0.05PO₄/C and LiFe_0.99Gd_0.01PO₄/C are 2.17 x 10^-4 S/cm, 1.54 x 10^-4 S/cm, and 2.02 x 10^-4 S/cm, respectively.

Abstract: The synthesis of LiFeSi_0.03P_0.97O₄/C (LFSP/C) composites have been done by solid state method. This study investigates the effects of carbon coating on the structure, microstructure and electrical conductivity of LFSP/C cathode materials. The carbon coating on Lithium Ferro Phosphate (LFP) plays a crucial role in determining its electrical conductivity. The variation of carbon content is 0wt.%; 6wt.%; 7wt.%; 8wt.% (LFP-0%, LFP-6%, LFP-7% and LFP-8%). The characterization was performed using X-Ray Diffraction (XRD), Scanning Electron Microscopy - Energy Dispersive X-ray (SEM-EDX), HighResolution-Transmission Electron Microscopy (HR-TEM) and LCR Meter tests. The XRD result have shown single-phase olivine (LiFePO₄) in all samples. The analysis microstructure using SEM have shown increasing carbon content can reduce agglomeration. The particles size of LFSP is 845.570 nm, and after coating carbon the particles size decreased up to 457.191 nm. The EDX results showed that the amount of atomic percentage for carbon tends to increase as the amount of carbon content increased. HR-TEM images indicates that the formation of carbon layer have formed, but not perfectly coat the LFP particle. The average carbon layer size is 78,31 nm with the size of LFSP particle is 352.82 nm. The LCR Meter result showed that LFP-7% had the largest electronic conductivity (2,275x10^-7 S/cm). The carbon coating led to significant enhancement in electronic conductivity from ~10^-9-10^-10 S/cm to ~10^-7 S/cm.