Patent ID: 8445144

Claim:
An additive for an electrolyte solution for an electrochemical device, said additive comprising a compound represented by the following formula: wherein R 1 and R 4 are each independently selected from the group consisting of a substituted or 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 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, and —COZ, wherein Z is a hydrogen atom or a substituted or unsubstituted alkyl group having 1 to 5 carbon atoms; R 2 and R 3 are each independently selected from the group consisting of an unsubstituted alkyl group having 1 and 3 to 5 carbon atoms, a substituted or unsubstituted alkoxy group having 1 to 5 carbon atoms, a substituted or unsubstituted phenoxy group, an 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 halogen atom, —NX 2 X 3 , wherein X 2 and X 3 independently represent a hydrogen atom or a substituted or unsubstituted alkyl group having 1 to 5 carbon atoms, 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.