Method for supplementing lithium for negative electrode of lithium ion battery

Abstract

The invention belongs to the technical field of lithium ion batteries, in particular to a method for supplementing lithium for a negative electrode of a lithium ion battery. The method comprises the following steps: spraying or dripping an organic lithium solution on a surface of a negative electrode in an inert atmosphere, so that lithium ions in the organic lithium solution are reverted to metal lithium which is embedded into the negative electrode; and drying the negative electrode. Compared with the prior art, in the method, the organic lithium solution is sprayed or dipped on the surface of the negative electrode evenly so as to realize lithium supplementation in a wet process, thereby effectively avoiding metallic lithium powders floating in the air in a dry process to ensure safe production; and the whole process is simple, the cost is lower, the amount of the lithium supplementation can be controlled accurately through the amount and the time by spraying or dripping the organic lithium solution so as to supplement the lithium evenly, thereby preventing lithium precipitation and deformation of the negative electrode and improving the initial efficiency of the battery. Therefore, the the energy density of the battery is improved. Additionally, the invention further discloses another method for supplementing the lithium for the negative electrode of the lithium ion battery.

Description

technical field [0001] The invention belongs to the technical field of lithium-ion batteries, and in particular relates to a method for supplementing lithium to negative plates of lithium-ion batteries. Background technique [0002] Lithium-ion batteries have become one of the most widely used secondary batteries due to their advantages of high voltage, high energy density and long cycle life. However, with the miniaturization of portable electronic devices and the continuous development of long standby time, as well as the use of high-power and high-energy devices such as electric bicycles and electric vehicles, the energy density of lithium-ion batteries as energy storage power sources has been increasingly raised. high demands. [0003] For the negative electrode sheet, part of the lithium will be consumed due to the formation of the solid electrolyte film (SEI film) during the first charging process of the battery, which will cause the loss of lithium in the positive el...

AI Technical Summary

Problems solved by technology

[0009] The purpose of the present invention is to: aim at the deficiencies in the prior art, and provide a kind of method for replenishing lithium to the negative plate of lithium ion battery, this method adopts "wet method lithium replenishment", can effectively avoid metal lithium powder in dry method when replenishing lithium Floating in the air ensures production safety, and the whole process is simple and the cost is low. The amount of lithium supplementation can be accurately controlled by the amount of organic lithium solution sprayed or dripped, and the time of spraying or dripping, so as to achieve uniform supplementation. The purpose of lithium is to overcome the shortcomings of uneven lithium intercalation, inability to accurately quantitatively intercalate lithium, harsh environmental requirements and high production costs in the prior art.