Silicon carbon lithium ion battery electrolyte and silicon carbon lithium ion battery using same

Abstract

A silicon carbon lithium ion battery electrolyte and a silicon carbon lithium ion battery using the same belong to the field of lithium ion battery materials. The electrolyte comprises a film-formingadditive accounting for 8% to 15% by weight of the total weight of the electrolyte. The film-forming additive comprises a phosphate ester/phosphite ester compound, fluoroethylene carbonate (FEC), ethylene sulfate (DTD) and lithium difluorophosphate (LiPO2F2). The electrolyte has excellent cycle performance. The phosphate ester/phosphite ester compound has chemical structural formulas shown by theformulas (I) and (II) which are described in the specifications.

Description

technical field [0001] The invention belongs to the field of lithium ion battery materials, in particular to a silicon-carbon lithium-ion battery electrolyte and a silicon-carbon lithium-ion battery using the electrolyte. Background technique [0002] As countries around the world have higher and higher requirements on the environment and stricter requirements on vehicle exhaust emissions, new energy vehicles have emerged as the times require, because lithium-ion batteries provide their power to reduce exhaust emissions. However, customers have higher and higher requirements for the mileage of electric vehicles, which requires continuous improvement of the energy density of lithium batteries. The use of high-energy-density silicon-carbon anode materials can greatly increase the energy density of batteries. However, the SEI film of the silicon-carbon negative electrode is unstable. During the cycle, the SEI of the negative electrode will be continuously destroyed and generate...

AI Technical Summary

Problems solved by technology

[0003] The purpose of the present invention is to solve the problem of instability of the existing silicon-carbon negative electrode SEI film, to provide a silicon-carbon lithium-ion battery electr...

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