Lithium-ion battery and its non-aqueous electrolyte

Abstract

The invention discloses a non-aqueous electrolyte. The non-aqueous electrolyte comprises a non-aqueous organic solvent, a lithium salt and an additive, and the additive comprises lithium tetrafluoroborate and at least one of unsaturated bond-containing dinitrile compounds of formula I and formula II. In the formula I and the formula II, R1, R2, A1 and A2 are independently selected from one or more of C0-C5 aliphatic alkyl groups; and R3, R4, A3 and A4 are independently selected from one or more of the hydrogen atom, the fluorine atom , the chlorine atom, an alkyl group and a phenyl group. Additionally, the invention also discloses a lithium ion battery containing the non-aqueous electrolyte.

Description

technical field [0001] The invention belongs to the field of lithium ion batteries, more specifically, the invention relates to a lithium ion battery and its non-aqueous electrolyte. Background technique [0002] Lithium-ion batteries have unique advantages such as high energy density, high working voltage, low self-discharge rate, long cycle life, and no pollution. They have been widely used as power sources in electronic products such as cameras and mobile phones. [0003] In recent years, the rapid development of smart electronic products has put forward higher requirements for the battery life of lithium-ion batteries, and the way people use digital products has also put forward additional requirements for the performance of lithium-ion batteries. For example, when people use a laptop computer, the lithium-ion battery is often in a full state after it is fully charged, and the lithium-ion battery will only discharge and work when it is away from the power supply, that is...

AI Technical Summary

Problems solved by technology

However, under high voltage, the oxidation activity of the positive electrode becomes higher, and the non-aqueous electrolyte is prone to electrochemical oxidation reaction on the surface of the positive electrode, and then decomposes to generate gas, causing irreversible capacity loss, resulting in a decrease in the cycle capacity retention rate of lithium-ion batteries.

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