Non-aqueous electrolyte and high-nickel ternary cathode material battery

Abstract

The invention provides an electrolyte, and the electrolyte comprises a lithium salt, an organic solvent and an additive A; the additive A comprises one or more kinds of alkylamine compounds, silicon nitrogen compounds and siloxane compounds. In order to improve the electrolyte, the non-aqueous electrolyte has one or more kinds of the alkylamines, compounds with Si-N bonds (the silicon nitrogen compounds) and the siloxane compounds. The non-aqueous electrolyte has extremely low free acid content, is applied to a lithium-ion battery with a high-nickel ternary cathode material and can effectively improve the circulation performance, high-temperature circulation performance and high-temperature storage performance of the lithium-ion battery.

Description

technical field [0001] The invention relates to the technical field of lithium-ion batteries, in particular to an electrolyte and a lithium-ion battery, in particular to a non-aqueous electrolyte and a high-nickel ternary positive electrode material battery. Background technique [0002] As the "engine" part of electric vehicles, the specific energy of lithium-ion power batteries is a key factor determining the mileage of a single charge of pure electric vehicles, which directly affects the technological development and popularization of electric vehicles. The specific energy of current lithium-ion power batteries largely depends on the specific energy of the cathode material. Increasing the discharge specific capacity of the positive electrode is one of the effective ways to increase the specific energy of the battery. [0003] Among many positive electrode materials, high nickel ternary lithium-ion battery positive electrode materials mainly include nickel cobalt lithium ...

AI Technical Summary

Problems solved by technology

The problems of the material itself are as follows: first, the Ni / Li mixed discharge during the cycle produces a phase transition reaction, which in turn induces the stress-strain effect, resulting in capacity decay during the material cycle; the second is the high delithiation state of Ni 4+ tends to reduce to Ni 3+ , Oxygen will be released in the material, and the thermal stability of the material will be deteriorated

But so far, the research direction on the electrolyte of this type of material is mainly on the conventional LiPF 6 However, these measures have a very limited effect on improving the cycle performance of high-nickel ternary cathode materials, and the cycle stability is still not ideal.

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