Characteristics of electric double layer capacitor using polyvinylalcohol-lithium salts solid electrolyte

Abstract

A composite of polyvinylalcohol (PVA) and lithium salts (LiBF/sub 4/) is prepared for the solid-state electrolyte of an electric double layer capacitor. The composite shows good ionic conductivity. An evaluation of the characteristics of the capacitor shows that the capacitance change, measured by a charge-discharge test with 2.2 V/spl sim/O V at 80 /spl deg/C for 800 hours, is about 10%. The gravimetric and volumetric capacitances are 10.0 F/g/spl sim/30.0 F/g and 16.0 F/cm/sup 3//spl sim/19.0 F/cm/sup 3/, respectively.