Polarizable electrode for electric double layer capacitor and electric double layer capacitor using the same

Abstract

The present invention provides a polarizable electrode for an electrical double layer capacitor which has good high-temperature storage characteristics and can prevent a decrease in electrostatic capacity and increase in internal resistance, and also provides an electrical double layer capacitor using the electrode. A polarizable electrode is formed by mixing Ketjen black, active charcoal and a polytetrafluoroethylene (PTFE) aqueous solution. An etched aluminum foil is used for the collector, and this etched aluminum foil is dipped in a phosphoric acid aqueous solution or an ammonium phosphate or other phosphate aqueous solution to thereby retain 15 to 115 mg/m2 of phosphorus on the surface of the etched aluminum foil. The electrostatic capacity per unit area on the surface of this etched aluminum foil is 50 to 350 μF/cm2.

Dependencies are inferred from the claim text.