Abstract: A quaternary ammonium salt of the formula (1), a composition containing the quaternary ammonium salt and an organic solvent, and an electrochemical device using the salt wherein R1 and R2 are both methyl and X? is BF4? or N(CF3SO2)2?.

Abstract: A quaternary ammonium salt of the formula (1), a composition containing the quaternary ammonium salt and an organic solvent, and an electrochemical device using the salt wherein R1 and R2 are both methyl and X? is BF4? or N(CF3SO2)2?.

Abstract: A quaternary ammonium salt of the formula (1), a composition containing the quaternary ammonium salt and an organic solvent, and an electrochemical device using the salt wherein R1 and R2 are both methyl and X? is BF4? or N(CF3SO2)2?.

Abstract: A quaternary ammonium salt of the formula (1), a composition containing the quaternary ammonium salt and an organic solvent, and an electrochemical device using the salt wherein R1 and R2 are both methyl and X? is BF4? or N(CF3SO2)2?.

Abstract: A quaternary ammonium salt of the formula (1), electrolytic solution and electrochemical device using the salt wherein R1 is straight-chain or branched alkyl having 1 to 4 carbon atoms, R2 is methyl or ethyl, and X? is a fluorine-containing anion.

Abstract: An electrolyte for an electrical double layer capacitor and an electrical double layer capacitor using the electrolyte are disclosed. The electrolyte has a low coefficient of viscosity, high conductivity, and high withstand voltage, and excels in long term reliability. The electrolyte for an electrical double-layer capacitor comprises a dimethyl carbonate and a compound of the following formula (1), wherein, m and n individually represent a natural number of 3-7, and X is a counter anion.

Abstract: An electrolyte for an electrical double layer capacitor and an electrical double layer capacitor using the electrolyte are disclosed. The electrolyte has a low coefficient of viscosity, high conductivity, and high withstand voltage, and excels in long term reliability. The electrolyte for an electrical double-layer capacitor comprises a dimethyl carbonate and a compound of the following formula (1), wherein, m and n individually represent a natural number of 3-7, and X? is a counter anion.

Abstract: An activated carbon for use as a polarized electrode is brought into contact with an organic compound which forms an azeotropic mixture with water, so that the activated carbon is impregnated with the organic compound. Then, the activated carbon impregnated with the organic compound is dried with heat to remove the azeotropic mixture of the organic compound and the water. The activated carbon is immersed in the organic compound to impregnate the activated carbon with the organic compound. Preferably, when the organic compound forms an azeotropic mixture with water, the azeotropic mixture contains 28 weight % of water or more. The organic compound preferably comprises at least one compound selected from the group consisting of benzene, chlorobenzene, ethyl acetate, methyl ethyl ketone, 1,4-dioxane, and methyl acetate, and more preferably comprises benzene.

Abstract: An electrochemical capacitor is provided having double-layer electrode elements interposed with a separator. The electrode elements being made of activated carbon and impregnated with a nonaqueous electrolytic liquid yields a capacitor with low internal resistance, greater capacitance and higher energy density. Methods for producing the activated carbon electrodes and the capacitor assembly are also described.

Abstract: An electrochemical capacitor has a pair of positive and negative electrode elements each having a solid electrode disposed on a surface of a current collector. The positive and negative electrode elements are disposed in confronting relation to each other with a separator interposed therebetween. The positive and negative electrode elements, together with an electrolytic solution, are housed in the casing. The solid electrode of the negative electrode element is made of a lithium vanadium oxide and an electrically conductive filler, and the solid electrode of the positive electrode element is made of activated carbon.