Electrolyte for lithium battery with silicon cathode and lithium battery with silicon cathode

Abstract

The invention relates to an electrolyte for a lithium battery with a silicon cathode. The electrolyte comprises a lithium salt, a solvent and an additive, wherein the additive comprises an additive M, the molar concentration of the lithium salt is 0.001 to 2 mol/L, and the additive M accounts for 0.1 to 10% of the mass of the electrolyte. The structural formula of the additive M is described in the specification; and in the formula, R1, R2, R3, R4 and R5 are independently alkoxy groups or halogenated alkoxy groups, R6 is an alkyl group or a halogenated alkyl group, halogenated halogen is any one selected from the group consisting of F, Cl and Br, halogenation is partial substitution or full substitution, m and n are integers in a range of 1 to 10, independently, and x is an integer in a range of 1 to 10. An organosilicon isocyanate compound containing a polyether chain can effectively improve charge and discharge performance of the lithium battery with the silicon cathode and reduce side reactions, so gas generation of the battery is reduced, and the cycle life of the battery is prolonged.

Description

technical field [0001] The invention belongs to the technical field of materials, and in particular relates to an electrolyte solution for a silicon negative electrode lithium battery and a silicon negative electrode lithium battery. Background technique [0002] Lithium-ion batteries have the advantages of high working voltage, large specific energy, no pollution, no memory effect, and long life. They are widely used in portable electrical devices such as mobile phones, digital cameras, and notebook computers. At the same time, they are used as an alternative energy source for petroleum in electric vehicles. And hybrid vehicles will also be applied on a large scale. Silicon anode has a large lithium storage capacity and is abundant in the earth, making it an ideal anode material for lithium-ion batteries. [0003] Using a silicon negative electrode as the negative electrode of a lithium-ion battery, during the charge-discharge cycle, the reversible formation and decomposit...

AI Technical Summary

Problems solved by technology

However, although this type of compound forms a film on the surface of the negative electrode, the fusion between the film structure and the silicon negative electrode is not sufficient, the charge and discharge performance is reduced, and the gas generation is very significant, and the battery expands greatly.

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