Patent ID: 8372547

Claim:
A non-aqueous electrolytic solution comprising: (I) a solvent for dissolving an electrolyte salt comprising: (A) a fluorine-containing carbonate, (B) a non-fluorine-containing cyclic carbonate, and (C) a chain ester represented by the formula (C): R 1 COOR 2 wherein R 1 is an alkyl group having 2 to 4 carbon atoms; R 2 is an alkyl group having 1 to 4 carbon atoms or a fluorine-containing alkyl group having 1 to 4 carbon atoms, and (II) an electrolyte salt, the component (A) is the fluorine-containing carbonate represented by the formula (A2): Rf 4 OCOORCf 5 wherein Rf 4 is a fluorine-containing alkyl group having 1 to 4 carbon atoms; Rf 5 is an alkyl group which has 1 to 4 carbon atoms and may have fluorine atom; and wherein the solvent (I) comprises the the component (A) in an amount of 20 to 80% by volume, the non-fluorine-containing cyclic carbonate (B) in an amount of 3 to 40% by volume and the non-fluorine-containing chain ester or the fluorine-containing chain ester (C) in an amount of 3 to 77% by volume to the whole solvent (I).