Electrolyte functional additive for lithium ion battery, lithium ion battery electrolyte and lithium ion battery

Abstract

The invention relates to an electrolyte functional additive for a lithium ion battery, a lithium ion battery electrolyte and a lithium ion battery, and belongs to the technical field of lithium ion batteries. The electrolyte functional additive for the lithium ion battery is prepared from the following components in parts by weight: 0.2-2 parts of vinylene carbonate; 0.5-2.5 parts of ethylene sulfate; 0.2-1 part of lithium difluorophosphate; 0.2-1 part of a film-forming agent; and 0.5-2.5 parts of fluoroethylene carbonate. The film-forming agent is at least one of tris(trimethylsilane) borateand tris(trimethylsilane) phosphate. When the electrolyte functional additive for the lithium ion battery is used for the lithium ion battery made of a high-capacity ternary positive electrode material, excellent SEI films can be formed on the surfaces of the positive electrode and negative electrode of the lithium ion battery, so that direct contact between an electrolyte and the surface of the positive electrode can be effectively prevented, meanwhile, the dissolution of metal ions is reduced, and the cycle performance of the battery is obviously improved.

Description

technical field [0001] The invention relates to an electrolyte functional additive for a lithium-ion battery, an electrolyte for a lithium-ion battery and a lithium-ion battery, belonging to the technical field of lithium-ion batteries. Background technique [0002] Energy is the basis for the existence and development of human society. Today's society based on mineral energy is increasingly confronted with crises of energy shortage and environmental pollution. In order to reduce the pollution emissions of urban vehicles and realize the development strategy of new energy vehicles, the development of electric vehicles is the current top priority. Since the commercialization of lithium-ion batteries in the 1990s, they have received extensive attention due to their superior performance in all aspects. However, with the gradual development of electric vehicles, people have put forward higher requirements for the energy density of lithium-ion batteries. [0003] At present, the...

AI Technical Summary

Problems solved by technology

The electrolyte improves the stability of the positive and negative electrodes of the battery by adding lithium difluorophosphate, vinylene carbonate and 1,2,3,4,5,6-hexamethylcyclotrisilazane, and effectively inhibits the transition metal ion Dissolution and oxidative decomposition of solvents can improve the cycle performance and storage performance of the electrolyte under high temperature conditions, but because the stability of the film formed on the positive and negative electrodes is still poor, the cycle performance of lithium-ion batteries needs to be further improved

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