Electric double-layer capacitor and its manufacturing method using an aqueous electrolytic solution

Abstract

An electric double-layer capacitor capable of maintaining a low leakage current over a long period of time even in a high temperature range, having high reliability in the high temperature range, and thereby making it possible to extend the life of an apparatus using the electric double-layer capacitor is provided. Further, a method for manufacturing such an electric double-layer capacitor is also provided. An electric double-layer capacitor and its manufacturing method are characterized in that an aqueous electrolytic solution containing a water-soluble electrolyte of which a Hammett acidity function H0 at a temperature of 25° C. is −2.8 or higher and a vapor pressure at a temperature of 100° C. is 400 mmHg or lower is used.

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