Aqueous Gel Electrolyte Based on Cross-Linked PVA Matrix for EDLC

Abstract

Alkaline polymer gel electrolytes mainly with modified polyvinyl alcohol (PVA) have been prepared for an electric double layer capacitor (EDLC). Their electrochemical characteristics were evaluated by impedance spectroscopy and constant-current charge/discharge measurement. The prepared gel electrolyte film with KOH exhibits excellent flexibility and an ionic conductivity of about 7×10⁻² S cm⁻¹ at 298 K. The gel electrolyte EDLC shows comparable discharge capacitance to that for EDLC containing a conventional aqueous electrolyte. These results suggest that the gel electrolyte based on the modified PVA is promising material for use in EDLC.