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 non-aqueous electrolyte of the lithium ion battery comprises a lithium salt, a non-aqueous organic solvent and an additive. The additive comprises a fluoroether compound with a structural formula 1 and an unsaturated phosphate compound with a structuralformula 2, and further comprises a cyclic sulfate compound with a structural formula 3 or 4, and R1, R2, R3, R4, R5 and R6 are respectively and independently selected from fluorine atoms and C1-C4 fluoroalkyl. R7, R8 and R9 are each independently selected from unsaturated hydrocarbon groups or fluorinated hydrocarbon groups of C1 to C4. R10 is hydrogen or C1-C5 alkyl, and n is an integer from 1 to5. The lithium ion battery prepared from the non-aqueous electrolyte of the lithium ion battery has relatively good wettability, low-temperature charging and discharging performance, high-temperaturestorage performance, high-temperature cycle performance and normal-temperature cycle performance, and low-temperature lithium precipitation can be effectively avoided.

Description

technical field [0001] The invention relates to the technical 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 battery is a kind of secondary battery, which has significant advantages such as high specific energy, high specific power, long cycle life, and small self-discharge. As lithium-ion batteries are used in more and more fields, the requirements for high voltage and high energy density of lithium-ion batteries are also getting higher and higher. In lithium-ion batteries, high-voltage ternary cathode materials (NCM or NCA) are widely used in electrical equipment due to their high energy density, environmental friendliness, and long cycle life. Density requirements are getting higher and higher, making it difficult for commercial lithium-ion batteries with ternary cathode materials to meet the r...

AI Technical Summary

Problems solved by technology

The electrolyte determines the lithium ion (Li + ) in the liquid phase, its matching with the electrode will also affect the wettability of the battery, and also participate in the formation of the solid electrolyte interface (SEI) film, which plays a key role in the performance of the SEI film, so the electrolyte may As a result, lithium-ion batteries have poor high-temperature storage performance, poor high-temperature cycle performance, and poor normal-temperature cycle performance; at the same time, the viscosity of the electrolyte increases at low temperatures, the conductivity decreases, and the impedance of the SEI film increases, so the electrolyte may also cause Li The low-temperature discharge performance of ion batteries is poor, and there is even a risk of low-temperature lithium precipitation

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