Non-aqueous lithium ion battery electrolyte and lithium ion battery

Abstract

The invention discloses a non-aqueous lithium ion battery electrolyte and a lithium ion battery. The non-aqueous lithium ion battery electrolyte comprises an electrolyte salt, a non-aqueous organic solvent and functional additives, and the functional additives are a low-impedance additive and a negative electrode film forming additive. The low-impedance additive and the negative electrode film forming additive are introduced to the non-aqueous lithium ion battery electrolyte and the lithium ion battery, and a compact and uniform SEI film having a high lithium ion conductivity can be formed during the first formation of the battery made of the non-aqueous lithium ion battery electrolyte, so the current distribution of the battery is uniform during the charge and discharge, and the ion conductivity of lithium ions is increased, thereby enhancing the room temperature cycle performances, the high temperature cycle performances, the high temperature storage performances and the low temperature cycle performances of the lithium ion battery.

Description

[technical field] [0001] The invention relates to a lithium battery, in particular to a non-aqueous lithium ion battery electrolyte and a lithium ion battery. [Background technique] [0002] With the pursuit of small volume and high energy density of the battery, the compaction density of the positive and negative electrodes is continuously increased or the high-capacity negative electrode material with poor cycle performance is used, which also brings a series of performance problems of the battery, such as poor cycle performance, Poor high-temperature performance, poor low-temperature performance and rate performance, easy to precipitate lithium during low-temperature charge and discharge. The cause analysis of the above problems found that a layer of SEI film will be formed on the surface of the negative electrode during the first charging process of the lithium-ion battery. In a low-temperature environment, if the formed SEI film is too thick and the film resistance is ...

AI Technical Summary

Problems solved by technology

In a low-temperature environment, if the formed SEI film is too thick and the film resistance is high, lithium ions cannot migrate through, and lithium precipitation will occur; during high-temperature cycling, if the formed SEI film is not dense and stable, the SEI film will Gradually dissolve or rupture, causing the exposed negative electrode to continue to react with the electrolyte, which consumes the electrolyte and reduces the battery capacity

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