Electrolyte for lithium ion battery and lithium ion battery containing electrolyte

Abstract

The invention discloses an electrolyte for a lithium ion battery. The electrolyte comprises the following components in percentage by weight: 10-15% of lithium hexafluorophosphate, 0.1-0.5% of hexamethylene diisocyanate, 0.5-2% of vinylethylene carbonate (VEC), 0.5-5% of fluoroethylene carbonate (FEC), 10-20% of ethylene carbonate (EC), 25-50% of diethyl carbonate (DEC), 10-20% of ethyl methyl carbonate (EMC), 3-5% of 1, 3-propane sultone (PS), and 1-3% of adiponitrile (ADN). The matching ratio of the components in the electrolyte is optimized, and the high-temperature type additive which refers to the hexamethylene diisocyanate is chosen, so that the storage performance of the lithium ion battery under a high temperature can be improved; and meanwhile, the additives, such as the FEC, the VEC and the like are reasonably utilized, so that the problem of relatively bad low-temperature performance caused after the HMDI is added can be effectively relieved.

Description

technical field [0001] The invention relates to the field of lithium-ion secondary batteries, in particular to a high-temperature storage electrolyte solution for polymer lithium-ion secondary batteries and a lithium-ion battery containing the electrolyte solution. Background technique [0002] With the continuous expansion of the application range of lithium-ion batteries, various terminal products have higher and higher energy density requirements for lithium-ion batteries, which also promotes the continuous development of traditional lithium-ion batteries to high voltage (such as 4.35V, 4.4V) system development. However, lithium-ion electrolytes operating at high voltages are more likely to decompose, especially when the charge-discharge cycle is performed in a high-temperature environment, the internal reaction of the battery is more intense, the decomposition of the electrolyte is accelerated, and it is difficult to form a stable SEI on the surface of the positive and n...

AI Technical Summary

Problems solved by technology

[0006] In the present invention, by optimizing the ratio of each component (solvent, lithium salt and additive) in the electrolyte, and selecting a high-temperature additive hexamethylene diisocyanate (HMDI), the lith

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