Abstract: An isocyanate electrolyte solution additive containing a sulfamide structural group has a structure of formula I: where R1 and R2 are identical or different, R1 and R2 are each independently selected from methyl, ethyl, butyl, methoxy, methanesulfonyl, ethanesulfonyl, fluorosulfonyl, trifluoromethanesulfonyl, perfluoroethylsulfonyl, benzenesulfonyl, alkyl-containing benzenesulfonyl, cyano/fluorobenzenesulfonyl and alkoxy-containing benzenesulfonyl, and R1 and R2 can be linked to form one of five-membered ring or six-membered ring. In the electrolyte solution additive, sulfonyl and the isocyanate structural group are organically linked, so the electrolyte solution additive has good thermostability, can function as an electrolyte solution stabilizing agent and avoids high temperature discoloration and acid value increase of the electrolyte solution.

Abstract: The present disclosure relates to an isocyanate electrolyte solution additive based on an imidazole structural group, belonging to the technical field of non-aqueous electrolyte solution additives of lithium batteries. The structural formula of the electrolyte solution additive is represented by formula I: R1, R2 and R3 are identical or different, the R1, R2 and R3 are each independently selected from one of hydrogen, methyl, ethyl, propyl, tert-butyl, trifluoromethyl, trifluoroethyl, perfluoroethyl, perfluoropropyl, cyanoethyl, phenyl, fluorophenyl, cyano-containing fluorophenyl, alkoxy-containing phenyl and alkyl-containing phenyl. The electrolyte solution additive is used for lithium ion batteries, which effectively inhibits the reduction in battery capacity, restricts the production of a gas caused by decomposition of an electrolyte solution and significant improvement in the service life of the battery during the high temperature cycle and high temperature storage.