POLARIZABLE ELECTRODE FOR ELECTRIC DOUBLE LAYER CAPACITOR AND ELECTRIC DOUBLE LAYER CAPACITOR USING THE SAME

摘要

Disclosed is a polarizable electrode for electric double layer capacitors, which enables an electric double layer capacitor to have good shelf characteristics at high temperatures, while preventing decrease in capacitance and increase in internal resistance.Also disclosed is an electric double layer capacitor using such a polarizable electrode for electric double layer capacitors. A polarizable electrode is formed by mixing ketjen black, activated carbon and an aqueous polytetrafluoroethylene (PTFE) solution. An aluminum etched foil is used for a collector, and this aluminum etched foil is immersed in an aqueous phosphoric acid solution or an aqueous phosphate solution such as ammonium phosphate, thereby having 15-115 mg/m2 of phosphorus held on the surface of the aluminum etched foil. The surface of the aluminum etched foil has a capacitance per unit area of 50-350 µF/cm2.