Non-aqueous electrolyte of lithium ion battery and lithium ion battery containing non-aqueous electrolyte

Abstract

The invention provides a non-aqueous electrolyte of a lithium ion battery and the lithium ion battery containing the non-aqueous electrolyte. The lithium ion battery non-aqueous electrolyte comprisesa lithium salt, a non-aqueous organic solvent and an additive. The additive comprises a compound having a structural formula represented by a formula I, R1 is C or N, R2 is a hydrogen or alkali metalelement, and R3 and R4 are alkali metal elements. The additive can optimize a positive electrode/electrolyte interface under a 4.4 V high-voltage system. A stable CEI film is formed on the surface ofa positive electrode to effectively prevent dissolution of transition metal, and the additive is further complexed with F<->, so that HF can be effectively removed, oxygen free radicals generated fromthe positive electrode material are absorbed, the stability of the positive electrode material is improved, and the charge-discharge reversibility in a cycle is improved. Meanwhile, the substituted alkali metal element can prevent active hydrogen connected to the nitrogen-containing heterocyclic nitrogen from reacting with a large amount of lithium ions in the electrolyte to consume the lithium ions. Therefore, by adopting the additive, the first coulombic efficiency, the cycle performance and the high-temperature performance of the lithium ion battery can be improved.

Description

technical field [0001] The invention relates to the field of lithium ion batteries, in particular to a nonaqueous electrolytic solution for a lithium ion battery and a lithium ion battery containing the nonaqueous electrolytic solution. Background technique [0002] Lithium-ion batteries are widely used in 3C digital, electric tools, aerospace, energy storage, power vehicles and other fields due to their advantages such as high specific energy, no memory effect, and long cycle life. The rapid development of electronic information technology and consumer products has a great impact on lithium-ion batteries. High battery voltage and high energy density can put forward higher requirements. In lithium-ion batteries, high-voltage ternary cathode materials (NCM or NCA) are widely used in portable electronic devices such as mobile phones and notebook computers, as well as electric vehicles and large storage devices due to their advantages such as high energy density, environmental ...

AI Technical Summary

Problems solved by technology

However, after the working voltage of the ternary power battery is increased, the performance of the battery such as charge and discharge cycles is reduced.

The reason may be: on the one hand, the positive electrode material is not stable enough under high voltage, on the other hand, the matching between the electrolyte and the material is not good, and the ordinary electrolyte will be oxidized and decomposed under high voltage conditions, resulting in high-temperature storage of the battery. Poor performance, poor high temperature cycle performance, poor low temperature discharge performance and poor safety, and the consumption of electrolyte leads to low capacity and low initial coulombic efficiency

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