Patent ID: 7082027

Claim:
A proton-conducting electric double layer capacitor comprising a positive electrode and a negative electrode facing each other in an electrolytic solution via a separator, wherein the positive electrode and the negative electrode each comprise as the active material a proton-conductive polymer in which only a proton participates in a charge/discharge, wherein the electrolytic solution comprising an aqueous solution of an organic or inorganic acid whereto a water-soluble N-containing heterocyclic compound is added, is used as the electrolytic solution, wherein said water-soluble N-containing heterocyclic compound is at least one compound selected from imidazole and the derivatives thereof represented by the following formula (1); triazoles and the derivatives thereof represented by the following formula (2) or (3); and pyrazole and the derivatives thereof represented by the following formula (4): where R represents individually and independently a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, an amino group, a carboxyl group, a nitro group, a phenyl group, a vinyl group, a halogen atom, an acyl group, a cyano group, a trifluoromethyl group, an alkyl sulfonyl group, or a trifluoromethylthio group.