High voltage electrolyte considering high and low temperature performance and lithium ion battery using the electrolyte

Abstract

The invention discloses high voltage electrolyte considering high and low temperature performance and a lithium ion battery using the electrolyte. The high voltage electrolyte comprises a non-aqueous organic solvent, an electrolyte lithium salt, an ether nitrile compound and a low impedance additive, wherein the non-aqueous organic solvent comprises a carbonate solvent and a linear carboxylic acid ester solvent with a wide liquid range; the electrolyte lithium salt is a combination of lithium hexafluorophate and lithium triflurosulfimide according to a molar ratio of 0.01-0.5; and the low impedance additive is a cyclic sulfate compound. The linear carboxylic acid ester solvent for perfecting the electrode / electrolyte interface is contained in the high voltage electrolyte, by means of the optimized combination of the ether nitrile compound, the lithium triflurosulfimide and the cyclic sulfate compound and other additives, a high voltage battery can be guaranteed to have excellent circulation performance, and meanwhile, the excellent high and low temperature performance of the high voltage battery of storage for 18 h in a full charge state at 85 DEG C and no lithium separation in the full charge state at 0 DEG C is considered.

Description

Technical field [0001] The invention involves the field of lithium -ion batteries, which specifically involves a high -electric electrolyte that takes into account high and low temperature performance and lithium ion batteries using the electrolyte. Background technique [0002] Lithium -ion batteries have the advantages of high working voltage, large capacity, long circular life, no memory effect and environmental friendliness, and are widely used in digital, energy storage, power and military aerospace and other fields.The electrolyte, as the carrier of ion transmission in the lithium ion battery, plays a vital role in the performance of the lithium -ion batteries. [0003] The high and low temperature performance of lithium -ion batteries are mainly affected by the following factors: (1), high temperature conditions are prone to exacerbate the catalytic decomposition of transition metal ions on electrolytes, and the decomposition of gas products directly causes the thickness o...

AI Technical Summary

Problems solved by technology

Affected by multiple factors such as the liquid range range of mixed organic solvents, the thermal stability of the SEI film, the interface impedance of the SEI film, and the high compaction of the negative electrode material, it is difficult for lithium-ion batteries to meet the high requirements of high and low temperature performance. High voltage electrolyte with high and low temperature performance

[0005] In the existing solutions for high / low temperature performance of high-voltage lithium-ion batteries, α-butyrolactone (GBL), succinonitrile (SN), propenyl sultone (RPS), lithium bisoxalate borate (LiBOB) ) and lithium difluorooxalate borate (LiDFOB) can improve the high-temperature or low-temperature performance of high-voltage batteries to a certain extent, but there are more or less difficulties in purification, poor compatibility of graphite negative electrodes, large interface impedance or high-temperature easy production gas problem

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