High-voltage electrolyte containing sulfate lithium salt additive and lithium ion battery containing electrolyte

Abstract

The invention belongs to the technical field of lithium ion batteries, and discloses a high-voltage electrolyte containing a sulfate lithium salt additive and a lithium ion battery containing the electrolyte. The high-voltage electrolyte containing the sulfate lithium salt additive comprises lithium hexafluorophosphate, an organic solvent and an additive, the organic solvent comprises one or more of chain carbonic esters, cyclic carbonic esters and carboxylic esters, and the additive comprises a sulfate lithium salt compound. The sulfate lithium salt compound has good high temperature resistance, can form a smooth and uniform film on the surface of an electrode, prevents further oxygenolysis of the electrode and an electrolyte, and reduces gas generation expansion of the battery after high temperature placement; meanwhile, the membrane has good permeability to lithium ions, impedance increase caused by membrane formation can be reduced, the conductivity of electrolyte in the lithium ion battery is effectively improved, and the cycle performance of the lithium ion battery is improved.

Description

technical field [0001] The invention relates to the technical field of lithium ion batteries, in particular to a high-voltage electrolytic solution containing a sulfate lithium salt additive and a lithium ion battery containing the electrolytic solution. Background technique [0002] In recent years, lithium-ion batteries have attracted much attention due to their higher energy density than other conventional ion batteries. With the rapid development of its application fields, people have put forward higher requirements for the energy density, rate performance, applicable temperature, cycle life and safety of lithium-ion batteries. [0003] At present, conventional carbonate-based high-voltage electrolytes have problems such as low oxidation potential and poor wettability with high-pressure positive electrode materials, which seriously restrict the practical application of high-voltage lithium-ion batteries. Lithium salt is the provider of lithium ions in the electrolyte an...

AI Technical Summary

Problems solved by technology

Vinylene carbonate (VC) is a common SEI film-forming additive. VC forms a dense SEI film by polymerizing on the surface of the negative electrode of lithium-ion batteries, thereby preventing further reduction and decomposition of the electrolyte on the surface of the negative electrode. , but VC under high temperature conditions, the stability of the SEI film deteriorates, which has a negative impact on the performance of lithium-ion batteries

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