Lithium ion battery electrolyte and lithium ion battery

Abstract

The invention provides a lithium ion battery electrolyte and a lithium ion battery. The lithium ion battery electrolyte comprises a non-aqueous organic solvent, a lithium salt and an additive, and the additive comprises an anhydride additive and a thianthrene additive. The invention further provides a lithium ion battery which comprises a positive electrode, a negative electrode, the lithium ion battery electrolyte and a diaphragm. The lithium ion battery electrolyte disclosed by the invention is used in a high-voltage battery, can improve the overcharge performance (1C 10V) of the lithium ion battery under a relatively wide working voltage (4.40 V to 4.50 V), and does not affect the electrochemical performance of the lithium ion battery.

Description

technical field [0001] The invention belongs to the technical field of batteries, and relates to a lithium-ion battery electrolyte and a lithium-ion battery. 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. With the continuous improvement of consumers' demand for the safety performance of lithium-ion batteries, it is required that lithium-ion batteries can take into account both electrical performance and safety. When the lithium-ion battery is overcharged, because the battery voltage rises rapidly with the increase of polarization, it will inevitably cause irreversible changes in the structure of the positive electrode active material and oxidative decomposition of the electrolyte, which will generate a large amount of gas and release a large amount of heat, resulting in the internal discharge of the battery. The pressure...

AI Technical Summary

Problems solved by technology

[0006] CN105702950A discloses a special safe lithium-ion battery for new energy vehicles. The lithium-ion battery of the invention overcomes the shortcoming of a narrow operating temperature range when traditional organic solvents are used as the electrolyte of lithium-ion batteries. It not only has excellent anti-overcharge performance, but also does not Affects other electrochemical properties of the battery. It has stable electrochemical properties and good flame retardancy when used at high temperatures. It has great application prospects in the field of new energy vehicles.

However, the maximum charging voltage of the lithium-ion battery of this invention still needs to be further improved during normal operation.

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