Lithium ion battery electrolytic solution and lithium ion battery

Abstract

The invention discloses a lithium ion battery electrolytic solution, which comprises a film-forming additive, wherein the film-forming additive comprises vinylene carbonate, ethylene sulfate, 1,3-propane sultone and lithium difluorophosphate, wherein the vinylene carbonate accounts for 0.2%-3% of the total mass of the electrolytic solution, the ethylene sulfate accounts for 0.5%-5% of the total mass of the electrolytic solution, the 1,3-propane sultone accounts for 0.2%-3% of the total mass of the electrolytic solution, and the lithium difluorophosphate accounts for 0.2%-2% of the total mass of the electrolytic solution. According to the invention, vinylene carbonate and ethylene sulfate in the electrolytic solution form a stable and compact SEI film on the surface of the negative electrode of the battery in the formation, charging and discharging processes, and 1,3-propane sultone and lithium difluorophosphate form a passive film on the surface of the positive electrode, so that the high-temperature gas production performance of the battery is improved, the damage to the negative electrode due to dissolution of positive electrode transition metal elements in the quick charge cycleprocess is inhibited, the film forming structure of the positive electrode and the negative electrode can be improved, the side reaction is reduced, and the battery is ensured to have good high-ratecharging performance and cycle life.

Description

technical field [0001] The invention belongs to the field of lithium ion batteries, in particular to a lithium ion battery electrolyte and a lithium ion battery containing the electrolyte. Background technique [0002] In recent years, lithium-ion batteries have been widely used in smartphones, tablet computers, smart wearables, power tools, and electric vehicles. With the acceleration of the pace of life and the development of electronic products, consumers have more urgent needs for shortening the charging time of lithium-ion batteries and improving the energy density of lithium-ion batteries, and accordingly put forward higher requirements for the charging speed of lithium-ion batteries. [0003] At present, various additives are added to the electrolyte to meet the needs of fast charging, but the existing lithium-ion battery electrolyte will lead to a large DCR and polarization of the battery, which will easily lead to lithium precipitation in the cycle of fast charging ...

AI Technical Summary

Problems solved by technology

[0003] At present, various additives are added to the electrolyte to meet the needs of fast charging, but the existing lithium-ion battery electrolyte will lead to a large DCR and polarization of the battery, which will easily lead to lithium precipitation in the cycle of fast charging and high rate. It is difficult to shorten the fast charging time and improve the fast charging performance

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