Lithium-replenishing additive, electrolyte for lithium ion battery, and lithium ion battery

Abstract

The invention discloses a lithium-replenishing additive, an electrolyte for a lithium ion battery, and a lithium ion battery. The electrolyte includes: a lithium salt; an organic solvent; a lithium-replenishing additive, and the lithium-replenishing additive includes LixSy, wherein 2<=x<=4, 2<=y<=8. The electrolyte can effectively avoid the floating of metal lithium powder in the air during dry method lithium supplementation and ensure the production safety, the whole process is simple, and the cost is low.

Description

Technical field [0001] The present invention relates to the field of materials, in particular to lithium supplement additives, electrolytes for lithium ion batteries and lithium ion batteries. Background technique [0002] Due to the characteristics of high energy density, long service life, and environmental protection, lithium-ion batteries have been widely used in mobile phones, notebook computers, digital cameras, and electric vehicles. Especially with the popularity of pure electric vehicles, people have put forward higher requirements on the performance of lithium-ion batteries. In order to ensure the mileage of electric vehicles and alleviate users’ anxiety about vehicle mileage, lithium-ion batteries are required to achieve higher energy density. In the current lithium-ion battery, during the first charge of the battery, part of the lithium is consumed due to the formation of the solid electrolyte membrane (SEI film), which results in a decrease in the first efficiency, ...

AI Technical Summary

Problems solved by technology

[0005] Although the first efficiency reduction and battery capacity reduction problems caused by the formation of SEI film can be alleviated by adopting strategies such as adding lithium supplement additives to the positive electrode and adding metal lithium sheets or lithium powder to the negative electrode, but in the above strategies, When added to the positive electrode material, the surface structure of the positive electrode material will change due to the irreversible loss of lithium supplement additives, the capacity of the positive electrode will be lost, and the improvement of the capacity of the entire battery or cell will be limited; the strategy of metal sheet lithium supplementation, because the negative electrode can The amount of lithium absorbed is far less than the amount of lithium provided by the metal sheet, which will lead to uneven lithium intercalation in the electrode and deformation of the substrate; on the one hand, there is a greater safety hazard in the operation of adding lithium powder (lithium powder is easy to floating), on the other hand, additives in powder form cannot guarantee the uniformity of lithium supplementation

Images