Electrolyte additive, electrolyte and lithium ion battery

Abstract

The application provides an electrolyte additive, an electrolyte and a lithium ion battery, the electrolyte additive comprises 1-9 parts of an additive a and 1-9 parts of an additive b in terms of mass fraction, the additive a is a mixture of one or more compounds with structures shown in formula 1 to formula 4, and the additive b is one or more of fluoroethylene carbonate, vinylene carbonate, vinyl ethylene carbonate, vinyl sulfate, pyridine, thiophene, propylene sulfite, 4-methyl ethylene sulfate, butanedinitrile and hexanedinitrile. The electrolyte additive of the application can replace part of the conventional additive, and the synergistic cooperation of the DOPO derived structure, the sulfonic acid group, the cyano group and the halogen substitution in the additive a can effectively improve the flame retardance of the electrolyte, and the high-temperature storage and cycle performance and the safety performance of the lithium ion battery are improved, so that the safety performance and the electrochemical performance of the battery can be considered.

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