Patent ID: 6858351

Claim:
An electrolyte composition comprising (1) a polymer having an ether linkage optionally having a crosslinkable functional group, (2) an additive comprising an organic silicon compound having an ethylene oxide unit, and (3) an electrolyte salt compound, wherein the ether linkage-containing polymer (1) is selected from the group consisting of (1-1) a copolymer comprising a structural unit represented by the following formula (i) and a structural unit represented by the following formula (ii), and (1-2) a copolymer comprising the structural unit (i), the structural unit (ii) and a crosslinkable structural unit represented by the following formula (iii); and the additive comprising the organic silicon compound having the ethylene oxide unit (2) is selected from the group of organic silicon compounds having the ethylene oxide unit represented by the following formulas (iv), (v) and (vi): wherein R 1 is an alkyl group, —CH 2 —O—(—CH 2 —CH 2 —O—) n —CH 3 or —CH 2 —O—CH[(—CH 2 —CH 2 —O—) n —CH 3 ] 2 and n is an integer of 0 to 12, wherein R 2 is a functional group having a reactive functional group, wherein A 11 , A 12 , A 13 and A 14 are, the same or different, —(—CH 2 ) p — and p is an integer of 0 to 3; X 11 , X 12 , X 13 and X 14 are, the same or different, a methyl group, an ethyl group, a propyl group or a butyl group; and a, b, c and d are an integer of 1 to 50, wherein A 21 , A 22 and A 23 are, the same or different, —(—CH 2 ) p —, provided that p is an integer of 0 to 3; X 21 , X 22 , X 23 and X 24 are, the same or different, a methyl group, an ethyl group, a propyl group or a butyl group; and h, i and j are an integer of 1 to 50, wherein A 31 and A 32 are, the same or different, —(—CH 2 ) p —, provided that p is an integer of 0 to 3; X 31 , X 32 , X 33 , X 34 , X 35 and X 36 are, the same or different, a methyl group, an ethyl group, a propyl group or a butyl group; and s and u are an integer of 1 to 50, t is an integer of 0 to 10, t<s and t<u.