Engineering Chemistry Vol. 5

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: The implementation of water-chitosan slurry is needed to achieve better battery, in terms of enviromentally friendly and cheapest cost. In this research, sodium-ion cathode batteries based on sodium iron phosphate and the water-chitosan slurry were successfully synthesized with the sol-gel method. The result of the X-Ray Diffraction (XRD) test confirmed the two phases of sodium iron phosphate, which are Na₃Fe₂(PO₄)₃ and Na₃Fe₃(PO₄)₄, with the percentage weight of the phases of 31.19% and 68.81%, respectively. Then, this sample was examined using Scanning Electron Microscope-Energy Dispersive X-ray (SEM-EDX) test, it is known that the morphology of particles look like agglomerate thin sponges and no other elements besides Na, Fe, P, and O were found in the sample. Cyclic Voltammetry (CV) dan Electrical Impedance Spectroscopy (EIS) tests were also carried out to determine the electrochemical performance of the cathode material. The CV test was carried out to determine the specific capacity value of each sample. From the test results, it is known that sodium iron phosphate cathode with PVDF binder had a higher specific capacity value than cathode with chitosan binder, which was 44.13 mAh/g and 26.78 mAh/g, respectively. From the EIS results, it was found that sodium iron phosphate cathode with chitosan binder had better electrical conductivity and Na⁺ ion diffusion, with values of 7.44×10^-3 S.cm^-1 and 1.48×10^-11 cm² s^-1 respectively.

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: 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: In this study, LiTi₂(PO₄)₃ (LTP) was synthesized by the addition of lithium fluoride (LiF) of 0 %, 5 %, and 10 wt.%. A wet solid-state reaction method is applied by mixing Li₂CO₃, TiO_2, and NH₄H₂PO₄ into a ball mill, then calcined at 900^o C for 12 hr. XRD pattern of Fluoride-doped LTP is indexed and found in two phases. First is the Nasicon phase (LiTi₂(PO₄)₃) with rhombohedral structure, and second, the Olivine phase (LiTiPO5) with orthorhombic structure at the addition of 5 % and 10 wt. % of LiF. The higher LiF decreases the cell volume while the crystallite size, particle size, and material density increase. The morphology of the Fluoride-doped LTP is increasingly homogeneous and more rectangle-shape. LTP 2, adding 10 wt. % of LiF, has high ionic conductivity at 4.77 10^-4 S cm^-1 as a promising candidate material for solid-electrolyte of lithium-ion battery.

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: A hybrid supercapacitor is an energy storage device that combines the properties of EDLCs and pseudocapacitors. In this research, the goal was to analyze the effect of hydrothermal temperature on the structure, morphology, and capacitive properties of the N-Doped reduced graphene oxide/Copper Chromite (N-Doped rGO/CuCr₂O₄) composite, which was being investigated as a potential material for hybrid supercapacitor electrodes. The method used was hydrothermal, with temperature variations of 120°C, 140°C, and 160°C. The structure and morphology of the composites were analyzed using Scanning Electron Microscope (SEM) and Energy Dispersive X-Ray Analysis (EDX), X-Ray Diffractometer (XRD), and Fourier Transform Infrared Spectrometer (FTIR). Meanwhile, the capacitance and conductivity values of N-doped rGO/CuCr₂O₄ were measured using Cyclic Voltammetry (CV) and Electrochemical Impedance Spectroscopy (EIS) tests. The results of the XRD tests showed that an increase in temperature led to a greater d_spacing value, indicating the presence of more substituted nitrogen atoms. This was supported by the results from EDX, which showed that the sample with a hydrothermal temperature of 160°C had the largest percentage of nitrogen. Nitrogen is important in increasing the conductivity of the material. The FTIR results revealed a covalent bond between Carbon (C) and Nitrogen (N). Meanwhile, the results of the CV test, performed at a scan rate of 5 mV/s and a potential window of 0-0.8 V, showed that the specific capacitance values were 99.5, 196.16, and 221.59 Fg^-1 for the samples with hydrothermal temperatures of 120°C, 140°C, and 160°C, respectively. The EIS test measured the conductivity values of the samples, which were 0.123, 0.518, and 0.549 S/m for the samples with hydrothermal temperatures of 120°C, 140°C, and 160°C, respectively. Thus, the specific capacitance values were influenced by the electrical conductivity of the materials and the nitrogen doping content in the electrode composite material.