Lithium supplementing method and lithium ion battery thereof

Abstract

The invention provides a lithium supplement method and a lithium ion battery thereof, and the lithium supplement method comprises the following steps: connecting a conductive shell with a negative electrode of a battery cell, and completing lithium supplement after liquid injection; and a lithium source is attached to the inner wall of the conductive shell. The lithium source is only attached to the inner wall of the conductive shell, lithium supplement to the negative electrode is achieved through the potential difference between the lithium source and the negative electrode, immediate liquid injection can be achieved after the lithium source is attached to the shell, the safety in the device manufacturing process is improved, the process is simple, and the cost is low; meanwhile, lithium supplement in the preparation process of the negative plate is not needed, so that the device production can be carried out by using the existing lithium battery production process, the equipment cost is saved, and the production efficiency is greatly improved; the energy density of the lithium ion battery prepared by the lithium supplementing method is obviously improved.

Description

technical field [0001] The invention belongs to the technical field of lithium ion batteries, and relates to a method for replenishing lithium, in particular to a method for replenishing lithium and a lithium ion battery thereof. Background technique [0002] Due to its high energy density and good cycle performance, lithium-ion batteries have been widely used in the fields of electronic communications, energy storage and power batteries. Improving the energy density of lithium-ion batteries is an important direction for the development of lithium-ion batteries. However, during the first charging process of existing lithium-ion batteries, the lithium ions of the positive electrode are embedded in the graphite of the negative electrode, and most of the lithium ions embedded in the discharge process can return to the positive electrode, but a small amount of lithium ions remain in the graphite and cannot return To the positive electrode, the consumption of this part of lithiu...

AI Technical Summary

Problems solved by technology

[0004] CN 112234160A discloses a lithium-replenishing method for the negative electrode active material of a lithium-ion battery. The lithium-replenishing method is to add the negative electrode active material into the organic lithium solution in two stages, and then obtain the second-stage lithium-replenishing active material, and then add the second stage The second-stage lithium supplement active material is added to the organic compound solution, calcined and cleaned to obtain the lithium supplement active material product; the operation of this method is cumbersome and difficult for industrial application

[0005] The above lithium supplementation method has the problems of complex process, strict environmental requirements and high process cost. For example, the amount of lithium supplementation in the electrolyte lithium supplementation method is small, and the cost is high, so it can only be used as an auxiliary means to supplement lithium; lithium metal additives supplement lithium The method can add lithium metal additives to the positive electrode to realize lithium supplementation, but this method will make the lithium metal compound in the prepared device easy to decompose after delithiation, and the decomposition product dissolves in the electrolyte, which will adversely affect other performances of the electrochemical device

Images