Solid polymer electrochemical capacitors using heteropoly acid electrolytes

An electrochemical capacitor utilizing a polyvinyl alcohol (PVA) and H₄SiW₁₂O₄₀ (SiWA) solid polymer electrolyte was developed. The electrolyte was deposited via precursor solution coating followed by thermal pressing and exhibited an ionic conductivity of 0.01 S/cm. The electrolyte has also shown good stability and cycle life. The performance of the solid polymer electrolyte-based capacitor was characterized using cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS), and was compared to a similar capacitor with an aqueous electrolyte.