Electrolyte for improving high-temperature performance of lithium ion battery and lithium ion battery

Abstract

The invention discloses an electrolyte for improving the high-temperature performance of a lithium ion battery and the lithium ion battery, and relates to the technical field of lithium ion batteries, the electrolyte comprises a lithium salt, a non-aqueous organic solvent, a high-temperature-resistant additive and a film-forming additive, the high-temperature-resistant additive is N-acetyl-N-sulfonyl pyrrole salt ionic liquid, and the film-forming additive is N-acetyl-N-sulfonyl pyrrole salt ionic liquid. According to the electrolyte additive N-acetyl-N-sulfonyl pyrrole salt ionic liquid, in the first charging and discharging process of a lithium ion battery, the electrolyte additive can participate in film generation on the surfaces of the positive electrode and the negative electrode of the battery, electrolyte consumption caused by the continuous reaction of the positive electrode material and the negative electrode material and electrolyte at the high temperature is reduced, and the service life of the electrolyte is prolonged. And meanwhile, gas production of the battery caused by film formation due to continuous reaction of the electrolyte is inhibited, so that the high-temperature storage and cycle performance of the battery is improved.

Description

technical field [0001] The invention relates to the technical field of lithium-ion batteries, in particular to an electrolyte and a lithium-ion battery for improving the high-temperature performance of the lithium-ion battery. Background technique [0002] Lithium-ion batteries have the advantages of high working voltage, high specific energy density, long cycle life, low self-discharge rate, no memory effect, and little environmental pollution. They have been widely used in various consumer electronics and power battery markets. In order to meet the requirements of high cruising range, normal use in high and low temperature environments, fast charging and long service life of electric vehicles, lithium-ion secondary batteries are required to have higher energy density, better high temperature performance and long cycle performance. [0003] At present, an effective way to increase the energy density of lithium-ion batteries is to use positive and negative electrode material...

AI Technical Summary

Problems solved by technology

High-nickel ternary positive electrode materials and silicon-carbon negative electrode materials have higher gram capacity and higher energy density when used in batteries. However, under high temperature conditions, high-nickel materials have high oxidation properties in the delithiated state. The negative electrode material has strong reactivity in the state of lithium intercalation, and it is easy to react with the electrolyte, resulting in high-temperature storage of the battery to produce gas and deteriorate the cycle performance

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