Electrolytic solution and lithium ion battery

Abstract

The invention relates to an electrolytic solution and a lithium ion battery, wherein the electrolytic solution comprises a lithium salt, a non-aqueous organic solvent and an additive, the additive comprises one or two selected from methylene methane disulfonate and ethylene sulfate, the lithium salt comprises lithium bis(fluorosulfonyl)imide, and the lithium bis(fluorosulfonyl)imide content is 5-15% of the total weight of the electrolytic solution. According to the present invention, the methylene methane disulfonate and / or the ethylene sulfate can significantly reduce the film forming impedance, the lithium bis(fluorosulfonyl)imide can improve the stability and the electrical conductivity of the electrolytic solution, reduce the production of hydrofluoric acid, inhibit the oxidative decomposition of non-aqueous organic solvents, and inhibit the dissolution of positive metal ions, such that the combination of the two materials can make the lithium ion battery have advantages of good low-temperature performance, fast charge performance and long cycle life.

Description

technical field [0001] The present application relates to the field of lithium-ion batteries, in particular, to an electrolyte and a lithium-ion battery. Background technique [0002] In recent years, due to the depletion of non-renewable resources brought by the automobile industry and the increasing pollution of the atmospheric environment, the world has focused on the field of electric vehicles (EV) and hybrid electric vehicles (HEV) that use clean energy. Lithium-ion batteries are known as green energy in the 21st century because of their high capacity, high voltage, high cycle stability, and environmental friendliness, and have broad application prospects. [0003] At present, nickel-cobalt lithium manganate cathode material combines the advantages of lithium cobalt oxide, lithium nickel oxide, and lithium manganate cathode materials such as energy density, power density, structural stability, and consistency of raw material preparation. Its cycle life, rate discharge p...

AI Technical Summary

Problems solved by technology

[0005] Usually, film-forming additives are added to the electrolyte to improve the performance of lithium-ion batteries. The film-forming additives of the electrolyte are generally vinylene carbonate, 1,3-propane sultone, etc., but their film-forming resistance is relatively large. Carbonate organic solvents are generally used as the liquid, and the conductivity of lithium ions is poor, so it is difficult to meet the comprehensive improvement of low-temperature performance, fast charging performance and cycle life of lithium-ion batteries.

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