Patent ID: 8422199

Claim:
An electrochemical capacitor comprising an element having a positive electrode with an electrode part mainly made of a polarizable electrode formed on a surface of an electric power collector made of a metal foil and a negative electrode with an electrode part mainly made of a carbon material occluding a lithium ion formed on the surface of an electric power collector made of a metal foil as a pair of electrodes wound or laminated in a state with a separator interposed between the positive electrode and the negative electrode facing with each other; an electrolyte; and an exterior member for storing the element and the electrolyte, wherein the electrolyte includes a solvent, an electrolyte salt represented by a following composition formula, and an acid inducing substance having a fluorine atom for an anion with a weight ratio of the acid inducing substance being in a range of 0.0001 to 2.0 wt % with respect to a sum of weight of the electrolyte salt and the acid inducing substance: Li[ P ( R f ) y F z ] (wherein R f is a perfluoro alkyl group (C n F 2n+1 ), n is a natural number, 1≦y<6, 1≦z<6).