Patent ID: 7754389

Claim:
An electrolyte solution in contact with an anode, comprising: a solvent including a carbonate derivative containing a halogen atom 4-fluoroethylene carbonate, wherein a content of the carbonate derivative in the solvent ranges from about greater than 10 vol % to about 65 vol %; a first anion represented by a formula: [B(CiH 2(i-2) O 4 )(CjH 2(j-2) O 4 )]— where i and j are integers of two or more; and a second anion except for the first anion, and wherein the anode includes a noncarbonaceous anode active material capable of inserting and extracting an electrode reacting material, and the noncarbonaceous anode active material is selected from the group consisting of a silicon-copper alloy and a tin-copper alloy.