Electrolyte and lithium ion battery

Abstract

The invention relates to an electrolyte, and the electrolyte contains an organic solvent, a lithium salt and an additive;, the additive comprises a gas production inhibition additive, a negative electrode film-forming additive, a positive electrode film-forming additive and a low-impedance additive, and the gas production inhibition additive is vinylene carbonate; the negative electrode film-forming additive is fluoroethylene carbonate and / or tris (trimethylsilane) phosphite ester; the positive electrode film-forming additive is adiponitrile and / or butanedinitrile; the low-impedance additive is one or more of lithium bis (oxalato) borate, lithium difluoro (oxalato) borate, lithium difluoro (oxalato) phosphate and lithium tetrafluoro (oxalato) phosphate. Through the coordination effect of the additive, the gas production rate of the electrolyte in the pre-charging process can be effectively inhibited, the cycle performance of the battery at high temperature is improved, and the production efficiency of the lithium ion battery is improved.

Description

technical field [0001] The invention belongs to the technical field of lithium ion batteries, and in particular relates to an electrolyte and a lithium ion battery. Background technique [0002] Under the current situation that a large amount of non-renewable energy is consumed and environmental conditions continue to deteriorate, lithium-ion secondary batteries, as a green and sustainable new energy technology, are widely used in portable devices, electric vehicles and energy storage; in recent years, although lithium Ion secondary batteries have made significant progress in the field of high-energy batteries, but their energy density is still difficult to meet the growing needs of consumer products; there are generally two ways to increase the energy density of batteries: choosing materials with high capacity and high compaction density and increasing the working voltage of batteries way. [0003] Graphite materials are one of the most common anode materials for lithium-i...

AI Technical Summary

Problems solved by technology

[0004]As an excellent negative electrode film-forming additive, vinylene carbonate decomposes to form a solid film layer on the surface of the negative electrode material prior to the electrolyte solvent, and this solid film can It effectively hinders the continued decomposition of the solvent on the surface of the material, so vinylene carbonate has the potential to inhibit gas production, but under high voltage or high temperature conditions, vinylene carbonate not only undergoes reductive decomposition on the negative electrode, but also occurs on the surface of the positive electrode material. Oxidative decomposition, resulting in low cycle efficiency due to uneven film formation, reduces the possibility of vinylene carbonate being used to suppress gas production

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