Characterization of nata de soya electrolyte membrane as a capacitor separator using (NH₄)₂SO₄

Tempeh and tofu production continues to grow rapidly in Indonesia. This means that the volume of liquid waste is also increasing dramatically. The problem is that most of this waste is disposed of in the environment and has the potential to pollute nature. In this study, Nata de Soya was used as a capacitor separator after undergoing a soaking process. This material was soaked for 30 minutes in an ammonium sulfate ((NH₄)₂SO₄) electrolyte solution. Researchers tested four different concentration levels, namely 22.5%, 25%, 27.5%, and 30%, to see how it performed. Characterization was performed using Cyclic Voltammetry (CV) to measure its specific capacitance and Electrochemical Impedance Spectroscopy (EIS) to measure the level of ionic conductivity. The test results show that increasing the electrolyte concentration has a positive effect on performance. After 30 minutes of soaking, the 30% concentration sample showed the highest capacitance compared to other samples, at 13.35 F/g, and also had the highest ionic conductivity, at 0.382 S/m. Based on these results, Nata de Soya membranes treated with varying electrolyte concentrations, including the 30% sample, show potential to be further explored as separator materials for environmentally friendly energy storage applications.