A non-aqueous electrolyte of a high-nickel ternary lithium ion battery and a high-nickel ternary lithium ion battery containing the electrolyte

Abstract

The invention discloses a non-aqueous electrolyte of a high-nickel ternary lithium ion battery and a high-nickel ternary lithium ion battery containing the electrolyte, which relates to the technicalfield of lithium ion batteries. The high nickel ternary lithium ion battery electrolyte comprises an electrolyte lithium salt, a non-aqueous organic solvent and a film forming additive. The film forming additive comprises vinyl sulfate and a phosphate ester compound having a structure of formula (I), optionally further comprising a conventional negative electrode film forming additive. The phosphate ester additive can form a protective film on the surface of the positive electrode material, thereby avoiding the generation of cracks in the NCM particles during the circulation process, reducingthe dissolution of transition metal elements at high temperature, and improving the normal temperature circulation performance, high temperature circulation performance and high temperature storage performance of the battery.

Description

technical field [0001] The invention relates to the field of lithium ion batteries, in particular to a high-nickel ternary lithium-ion battery non-aqueous electrolyte and the high-nickel ternary lithium-ion battery of the electrolyte. Background technique [0002] Lithium-ion batteries are widely used in 3C digital products, power tools, electric vehicles and other fields due to their advantages such as high working voltage, high energy density, long life, wide working temperature range and environmental friendliness. Especially in the 3C digital field, in recent years, mobile electronic devices, such as smart phones, have become lighter and thinner, which has put forward higher requirements for the energy density of lithium-ion batteries. [0003] In order to improve the energy density of lithium-ion batteries, a common measure is to use high-voltage positive electrode active materials, but the positive electrode material will have certain defects under high voltage, and th...

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Problems solved by technology

However, as the charge and discharge progress, the negative electrode active material will repeatedly expand and contract, which may cause the SEI film to rupture or gradually dissolve, and the active sites on the exposed negative electrode material continue to react with the electrolyte to form new SEI film, accompanied by the generation of a large number of by-products, and gas generation at the same time, causing the separation between the positive and negative electrodes and the separator, and greatly consuming lithium ions in the electrolyte, reducing the cycle performance of lithium-ion batteries

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