Papers by Keyword: Ionic Conductivity

Abstract: The semi-crystalline nature of bio-based solid polymer electrolytes (SPE) can impede ionic mobility, thereby reducing their ionic conductivity. One established method to enhance the ionic conductivity of SPE involves the addition of fillers. In this study, SPE was prepared using a solution casting method, comprising carboxymethyl cellulose (CMC) as the biopolymer host, lithium bis-trifluoromethanesulfonimide (LiTFSI) as the charge carrier, and zinc oxide (ZnO) as the nanofiller. We investigated the impact of ZnO on the electronic and chemical properties of the CMC-LiTFSI SPE through Electrochemical Impedance Spectroscopy (EIS), Fourier Transform Infrared spectroscopy (FTIR) and X-ray diffraction analysis (XRD). The highest ionic conductivity of 1.94 x 10^-6 S/cm was achieved with 4 wt.% ZnO. FTIR spectra demonstrated complexation between CMC, LiTFSI salt, and ZnO nanofiller. XRD analysis indicated an improvement in the amorphous nature as ZnO was added to CMC-LiTFSI system, which explained the increase in ionic conductivity. In conclusion, ZnO present a promising choice as a nanofiller to enhance the ionic conductivity a of the CMC-LiTFSI SPE system. Keywords: Solid polymer electrolyte; carboxymethyl cellulose; zinc oxide nanofiller; ionic conductivity

Abstract: This study aims to analysized the effect of addition doped metal (Ti and Zn) on NASICON structure to morphology, materials structure, and electrochemical performance especially ionic conductivity properties. NASICON is a sodium super ionic conductor that it could be as solid electrolyte batteries. One of the problems that exist in the secondary battery is the low working temperature of the electrolyte, which makes it easy to explode when exposed to free air. The common electrolyte in liquid phase, so NASICON as replacement alternative. The synthesis method used is the solid-state reaction method by mixing sodium carbonate, silicon dioxide, zirconium oxide, ammonium dihydrogen phosphate, doped metal (titanium oxide and zinc oxide) and some anhydrous ethanol into a planetary ball mill, dried then calcined. Then the material is pressed to produce pellets and the sintered. The doping used varies from 0 to 5 mol% of titanium and zinc. XRD results showed that all variations in titanium doped had found rhombohedral and monoclinic. whereas in zinc doping also have those phase. The highest ionic conductivity is 7.8x10^-3 S/m on 2% mol Zinc Addition

Abstract: The increasing of need for portable electrical energy makes the demand for rechargeable batteries high. Aluminum-ion battery with Solid Polymer Electrolyte (SPE) produced from the natural polymer corn starch with salt additive has the potential to be developed. The flexibility and resilience of SPE are enhanced by glycerol (C₃H₈O₃). Throughing gelatinization of the linear monomer chains to become amorphous, the space for the ions in it is more free so that the ionic conductivity is high. By means of solution casting, heating temperature of 50°C for 9 hours found SPE with a strong structure. With the same concentration CS-Al has a higher conductivity with σ = 4.93 x 10^-5 S/cm than CS-Na whose value is σ = 2,92 x 10^-5 S/cm. This is due to the SPE CS-Al show more amorphous structure which allow more flexible ionic segmental motion. This is in accordance with XRD resulting which shows that the addition of aluminum nitrate salt is more amorphous than sodium acetate; the shift in peak pattern is also greater due to cation intercalation Al³⁺ with corn starch. FTIR is the result found that nitrate fixed by corn starch, indicated a change in the hydroxyl group of corn starch amylopectin. SEM photo of result also showed aluminum nitrate salt ion more easily in overcoming than sodium acetate. The indicate of SPE was more homogeneous because corn starch was already intercalated. They are combined to Al³⁺ and NO₃^- ions. With this value it can be an appropriate reference for developing SPE on Aluminum-ion batteries with aluminum nitrate salts have higher performance and environment friendly Keywords: Aluminum-ion battery, Solid Polymer Electrolyte, corn starch, ionic conductivity, and Amorphous

Abstract: Solid polymer electrolyte (SPE) is a safer alternative to use than liquid electrolytes. This research focuses on the highest conductivity with fly ash filler in solid polymer electrolyte (SPE) based on corn starch, using the solution casting method. The crystallinity and interaction between fly ash and Na⁺ ions of solid polymer electrolyte were seen by X-ray Diffraction (XRD), then Fourier Transform Infra-Red (FTIR), showing a shift in functional groups due to the interaction of SiO₂ in fly ash and Na⁺ ions, and surface morphology forms was observed by Scanning Electron Microscopy (SEM). Ionic conductivity was analyzed by Electrochemical impedance Spectrometry (EIS). solid polymer electrolyte with fly ash showed the highest ionic conductivity 2,51 x 10^-4 S/cm, at room temperature with addition fly ash 10%. the highest conductivity result was corresponding with amorphous peak with same concetration on XRD. SPE based on corn starch with Fly ash filler has potential to be used as a solid polymer electrolyte in supercapacitors.

Abstract: This study examined the use of sodium acetate salt as an ionic dopant in biodegradable solid polymer electrolyte (SPE). In the solution casting method for making polymer electrolyte, rice starch is used as the host polymer and glycerol is used as the plasticizer. The characteristics of SPE film were investigated using X-Ray Diffraction (XRD), Fourier Transform Infrared (FT-IR), and Thermogravimetric Analysis (TGA). Salt enhances the amorphous structure by decreasing the crystallinity of the polymer. Alternatively, it decreases the temperature of thermal breakdown. In addition, the biodegradability of SPE was investigated using the soil burial method. Electrochemical Impedance Spectroscopy (EIS) was used to evaluate the ionic conductivity behavior and temperature dependent of SPE. The 35% sodium acetate salt addition makes the supercapacitor's electrolyte have the highest ionic conductivity at room temperature, which is 5.57x10^-4 S/cm.

Abstract: Prices of lithium raw materials keep on increasing exponentially due to their heavy consumption for lithium batteries used in portable electronic devices as well as automobiles. Also, the global lithium deposits are very limited. Hence, sodium-ion batteries (SIBs) have been heavily investigated as cheaper alternatives to expensive lithium-ion batteries, mainly due to the abundance of sodium raw materials. However, one of the major bottlenecks faced by the material research community to commercialize SIBs is the poor ionic conductivity of sodium-ion conducting electrolytes at ambient temperature, especially in the solid-state. Very recently, quasi-solid state polymer electrolytes (QSSPEs) have been proposed to overcome this challenge. In this work, a set of QSSPEs have been synthesized by using poly (vinylidene fluoride-co-hexafluoropropylene) (PVdF-HFP) host polymer and NaBF₄ ionic salt dissolved in EC/PC plasticizer/solvent mixture. The highest conducting composition; 6 PVdF-HFP: 14 NaBF₄: 40 EC: 40 PC (wt.%); showed an ambient temperature ionic conductivity of 4.1x10^-3 S cm^-1. The activation energy is almost same for all the sample compositions studied in this work suggesting that the activation process is mainly controlled by EC/PC. DC polarization test on highest conducting electrolyte composition with a configuration of SS/QSSPE/SS revealed that the electrolyte is predominantly ionic conductor with negligible electronic conductivity; a much desired property for a good electrolyte. Linear sweep voltammetric studies confirmed that the electrochemical stability window of the highest conducting electrolyte is about 3.6 V. This highest conducting electrolyte composition is found to be highly suitable for practical applications in sodium batteries.

Abstract: Copper sulphide quantum dots were synthesized by a simple chemical route using ammonia (aq.) as a complexing agent in PVA matrix. Copper acetate monohydrate and thiourea were used as precursors. The particle sizes as obtained from XRD results were found to be in good agreement with those of HRTEM. The UV-Vis. absorption and PL emission spectra exhibited a systematic blue shift of absorption and emission respectively confirming quantum confinement effect in the synthesized quantum dots. The band gap as estimated from Tauc-plot increased from 3.26eV to 3.92eV with change of concentration of complexing agent. The FTIR spectra exhibited Cu-S stretching peaks characteristic of CuS. Ionic contributions of the electrolytic ionic CuS solution as measured by a standard conductivity cell clearly showed the semiconducting behavior of the product material. The synthesized material may be exploited in fabrication of an optoelectronic device in UV-blue region.

Abstract: The solid polymer electrolyte (SPE) consists of polylactic acid (PLA) with different compositions of lithium perchlorate (LiClO₄) were prepared by using the solution casting method. The conductivity and dielectric properties of the SPE system were studied by using an impedance spectroscopy technique with a frequency ranging from 0.1 Hz to 100 MHz. The optimum composition of the LiClO₄ in the PLA based electrolyte system is 50 %. The highest ionic conductivity value of the PLA-LiClO₄ electrolyte is 2.66 x 10^-5 Scm^-1. The dielectric permittivity, ɛ′ shows high magnitude in the lower frequency due to electrode polarization (EP) effect and become to decrease at high frequency. The magnitude of ɛ′ increases up to 50 % of LiClO₄ in the electrolyte system. The loss tangent was used to measure the relaxation time of the electrolyte system. The shortest relaxation time is PLA- LiClO₄ polymer electrolyte system is 7.98 × 10−6 s. The electric modulus, M′ and M′', increases with frequency, indicating that the force of charge carriers increases in depletion and accumulation regions at room temperature.

Abstract: All-solid-state battery is a promising next-generation energy storage and conversion device and the development of solid electrolyte is very important as the core of all solid-state batteries. Herein lithium-indium chloride solid electrolyte is successfully prepared and the ionic conductivity is increased from 1.07 to 1.41 mS/cm by optimizing the vacuum parameter in the process of preparation. The samples have typical C2/m space group of cubic crystal system, and the vacuum optimized sample has more regular ion arrangement, better crystallinity and fewer lattice defects. The prepared sample is used as the electrolyte layer and the electrolyte part of the composite cathode, and the layered oxide LiNi_0.6Co_0.2Mn_0.2O₂ without surface modification was used as the active material. After assembling the cell, the initial discharge specific capacity of the cell was tested to be 157.5mAh/g. In addition, the phase transition of the composite cathode is analyzed under different charge and discharge state. It is found that the use of the lithium-indium chloride solid electrolyte in composite electrode does not affect the REDOX reaction of LiNi_0.6Co_0.2Mn_0.2O₂ layered oxide, indicating that the electrolyte material is stable and compatible with layered cathode material, showing its excellent application prospect.

Abstract: Global lithium deposits have been consumed a lot because of the heavy usage of lithium-ion batteries (LIBs) in almost all portable electronic devices and in automobiles. Due to the very limited global lithium resources, the so-called ‘batteries beyond lithium-ion’ such as sodium-ion batteries (SIBs) are becoming popular, particularly in the R&D level. One of the common problems in the commercial level production of SIBs is the synthesis of suitable electrolytes with sufficient ambient temperature ionic conductivities. In this work, a set of novel gel-polymer electrolytes (GPEs) based on poly (methyl methacrylate) (PMMA) host polymer have been synthesized and characterized by electrochemical impedance spectroscopic (EIS), DC polarization and cyclic voltammetric (CV) techniques. The optimized PMMA-NaClO₄-EC-DMC GPE composition (10:14:38:38 wt.%) showed an ambient temperature ionic conductivity of 8.4 mS cm^-1. Ionic conductivity vs inverse temperature showed Arrhenius behavior with almost same activation energies of 0.16 eV for all the compositions studied. DC polarization test on SS/GPE/SS configuration showed that the best conducting composition is dominantly an ionic conductor (t_ion ~ 0.998) with negligible electronic conductivity, which is highly desirable to avoid short circuits within the cell. The CV test on best conducting composition revealed that the electrochemical stability window (ESW) of these GPEs is about 4 volts (- 2 to + 2 volts). This optimized composition with highest ambient temperature ionic conductivity and negligible electronic conductivity seems to be a promising candidate for practical applications in sodium-ion secondary batteries.