Non-aqueous electrolyte for lithium ion battery and lithium ion battery comprising same

Abstract

The invention provides a non-aqueous electrolyte for a lithium ion battery and the lithium ion battery comprising the non-aqueous electrolyte. The non-aqueous electrolyte comprises a lithium salt and a non-aqueous organic solvent, and further comprises at least one of compounds as shown in a formula 1 and at least one of compounds as shown in a formula 2, wherein the compounds can form protective films at a positive electrode and a negative electrode, through the synergistic effect between the protective films, the positive electrode is protected while the negative electrode is protected to certain extent, and the lithium ion battery has better high-temperature storage performance and cycle performance and meanwhile has low-temperature performance.

Description

technical field [0001] The invention belongs to the technical field of electrolyte solution for lithium ion batteries, and in particular relates to a nonaqueous electrolyte solution for lithium ion batteries and a lithium ion battery including the nonaqueous electrolyte solution. Background technique [0002] Since its commercialization, lithium-ion batteries have been widely used in digital, energy storage, power, military aerospace and communication equipment and other fields because of their light weight, high specific energy, no memory effect, and good cycle performance. With the wide application of lithium-ion batteries, consumers have put forward higher requirements for the energy density, cycle life, high temperature performance, safety and other performance of lithium-ion batteries. To improve the energy density, on the one hand, it is possible to increase the charging voltage of the positive electrode, or to use a silicon negative electrode with better capacity. Mo...

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Problems solved by technology

[0003] At present, most lithium-ion battery products have the problem that high-temperature performance and low-temperature performance cannot be balanced. For this reason, additives are usually added to the electrolyte to improve the high-low temperature performance of lithium-ion batteries.

However, when the general additives have better high-temperature effects, the impedance is larger, and the high-temperature effects of low-impedance additives are lacking, so it is difficult to obtain a non-aqueous electrolyte for lithium-ion batteries with both high and low temperature performance.

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