Electrolyte solution and electrochemical capacitor using same

Abstract

The present invention provides an electrolyte highly reliable in charge and discharge in a high voltage condition, and an electrochemical capacitor using the same. The electrolyte of the present invention includes a solvent, an electrolyte salt having an anion having a perfluoro alkyl group represented by a following composition formula, and an acid inducing substance having a fluorine atom for an anion, characterized in that the weight ratio of the acid inducing substance is in a range of 0.0001 to 2.0 wt %: MX+[Q(Rf)yFz]X− (wherein Q is a group 13 or group 15 element in the periodic table, Rf is a perfluoro alkyl group (CnF2n+1), n is a natural number, 1≦y<6, 1≦z<6, MX+ is a cation of Xth valence, and X is a natural number from 1 to 3). Thereby, since excessive electric potential decline of the negative electrode by the electrolyte salt and destruction of the negative electrode protection film by HF are restrained at the same time, deterioration of the cycle characteristics is restrained even in the case of charge and discharge in a high temperature or high voltage condition.

Dependencies are inferred from the claim text.