Patent ID: 7745058

Claim:
A non-aqueous electrolyte composition comprising: an electrolytic salt; a non-aqueous solvent containing ethylene carbonate having a mass ratio ranging from 5% or more to less than 60%, propylene carbonate having a mass ratio of greater than 0% and less than 40%, and diethyl carbonate having a mass ratio of 40% to 70% as a mass ratio, respectively; an unsaturated cyclic carbonic ester, wherein the unsaturated cyclic carbonic ester is vinylethylene carbonate; and a high molecular compound wherein said high molecular compound is at least one kind selected from the group consisting of polyvinyl formal, polyacrylic acid ester, and polyvinylidene fluoride, wherein the vinylethylene carbonate included in the non-aqueous solvent is in an amount ranging from 0.1 to 2% as a mass ratio, and wherein the mass ratio of the ethylene carbonate, the propylene carbonate, the diethyl carbonate, and vinylethylene carbonate total 100% of the mass of the non-aqueous solvent.