Panasonic Corporation

Panasonic Intellectual Property Management Co., Ltd.

Shotaro Doi

Hideki Shimamoto

Susumu Nomoto

Kiyohiro Isii

Atsuro Shirakami

An electrochemical capacitor includes electrolytic solution, a capacitor element, and a housing. The electrolytic solution contains cations, anions, solvent formed of materials other than lactones, and a lactone component. The capacitor element includes a negative electrode, a positive electrode, and a separator. The negative electrode includes an electrode layer capable of storing the cations, and the positive electrode includes a polarizable electrode layer and confronts the negative electrode. The separator is disposed between the negative and positive electrodes, and they are layered or wound together. The capacitor element is impregnated with the electrolytic solution. The housing accommodates the capacitor element and the electrolytic solution that contains the lactone component in a quantity ranging from 0.001 wt % to 5 wt % (inclusive) relative to the solvent.

Electrochemical capacitor

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 %:()](wherein Q is a group 13 or group 15 element in the periodic table, Ris a perfluoro alkyl group (CF), n is a natural number, 1&#x2266;y&#x3c;6, 1&#x2266;z&#x3c;6, Mis 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.

Growing community of inventors

Osaka, Japan

Shotaro Doi