Patent ID: 7799471

Claim:
An electrochemical device comprising a cathode, an anode, a separator interposed between the cathode and the anode, and a liquid electrolyte, wherein the liquid electrolyte comprises: (a) an electrolyte salt; (b) an organic solvent; and (c) at least one compound selected from the group consisting of compounds represented by the following formula 1 and compounds represented by the following formula 2: wherein each of R 1 , R 2 and R 3 independently represents a hydrogen atom or a C1˜C6 lower alkyl group; R 4 represents a single bond or X represents each of n and m represents an integer of 0˜1000, each of p and q is an integer of 0˜20 with the proviso that p and q cannot represent 0 at the same time, and r is an integer of 1˜6; and each of i and j represents an integer of 1˜1000, and s is an integer of 1˜20.