High-temperature lithium ion battery electrolyte and lithium ion battery

Abstract

The invention relates to a high-temperature lithium ion electrolyte and a battery containing the electrolyte. The electrolyte comprises an additive A, wherein the additive A is a thiophosphate compound containing alkynyl; different from common unsaturated phosphate ester at present, only one triple bond is reserved in the compound, and oxygen atoms are replaced by sulfur of the same group so thatthe impedance formed when the compound participates in positive electrode film formation is relatively small, the low-temperature performance of the battery is not influenced, and the compound has a lower oxidation potential and the compound is more easily oxidized at the positive electrode to participate in film formation, the damage effect of the electrolyte on the positive electrode at high temperature is prevented and the purpose of improving the high-temperature performance is achieved.

Description

technical field [0001] The invention belongs to the technical field of lithium ion batteries, and in particular relates to a high-temperature lithium ion battery electrolyte and a lithium ion battery using the electrolyte. Background technique [0002] In recent years, the application fields of lithium-ion batteries have expanded rapidly, especially in other applications such as electric vehicles and large-scale energy storage power stations. The demand for high energy density of batteries has become more urgent. [0003] In order to achieve higher energy density requirements, it is generally achieved by increasing the working voltage of lithium-ion batteries or using high-nickel materials. The arrival of the era of high voltage or high nickel makes it extremely important to develop new electrolyte additives. In the non-aqueous organic electrolyte in the high-voltage (above 4.5V) battery system of the traditional electrolyte, the charging process will have a side reaction w...

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Problems solved by technology

[0007] The additives disclosed in the above documents are sulfur-containing additives or phosphorus-containing additives. The compound does not contain an alkynyl group, and the impedance is relatively large when forming a positive electrode film of a lithium-ion battery, so it cannot form a stable passivation film.

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