Patent ID: 8227116

Claim:
A secondary battery comprising: a positive electrode; a negative electrode; and an electrolyte solution comprising an aprotic solvent having at least an electrolyte dissolved therein, wherein the positive electrode comprises a lithium-manganese composite oxide having a spinel structure as a positive electrode active material, and the electrolyte solution comprises a compound represented by the general formula (1): wherein R 1 and R 4 independently represent an atom or a group selected from a hydrogen atom, a substituted alkyl group having 1 to 5 carbon atoms, a substituted or unsubstituted alkoxy group having 1 to 5 carbon atoms, a substituted or unsubstituted fluoroalkyl group having 1 to 5 carbon atoms, a polyfluoroalkyl group having 1 to 5 carbon atoms, —SO 2 X 1 , wherein X 1 is a substituted or unsubstituted alkyl group having 1 to 5 carbon atoms, —SY 1 , wherein Y 1 is a substituted or unsubstituted alkyl group having 1 to 5 carbon atoms, —COZ, wherein Z is a hydrogen atom or a substituted or unsubstituted alkyl group having 1 to 5 carbon atoms, and a halogen atom; and R 2 and R 3 independently represent an atom or a group selected from the group consisting of an unsubstituted alkyl group having 1 to 5 carbon atoms, a substituted or unsubstituted alkoxy group having 1 to 5 carbon atoms, a substituted or unsubstituted phenoxy group, a substituted or unsubstituted fluoroalkyl group having 1 to 5 carbon atoms, a substituted or unsubstituted fluoroalkoxy group having 1 to 5 carbon atoms, a polyfluoroalkoxy group having 1 to 5 carbon atoms, a hydroxyl group, a halogen atom, —NX 2 X 3 , wherein X 2 and X 3 represent a hydrogen atom, and —NY 2 CONY 3 Y 4 , wherein Y 2 to Y 4 independently represent a hydrogen atom or a substituted or unsubstituted alkyl group having 1 to 5 carbon atoms, wherein the compound represented by the general formula (1) is contained in the electrolyte solution in an amount of 0.1 to 5.0% by weight based on a total weight of the electrolyte solution.