Preparation method of lithium ion battery negative electrode for reducing irreversible capacity loss

Abstract

The invention discloses a preparation method of a lithium ion battery negative electrode for reducing irreversible capacity loss. The preparation method mainly comprises the following steps of (1) weighing a negative electrode active substance, a conductive agent, a binding agent, a surfactant, a lithium salt and water, and then dissolving the lithium salt in the water accounting for 10-20% of total water to obtain a lithium salt solution for use; (2) uniformly mixing the surfactant and the remaining water, and then adding and uniformly dispersing the conductive agent to form a conductive adhesive; (3) adding and dispersing the negative electrode active substance in the conductive adhesive, adding the binding agent, uniformly stirring, and then carrying out vacuum defoaming to obtain a negative electrode paste; and (4) uniformly applying the negative electrode paste onto the surface of the negative electrode current collector, uniformly spraying the lithium salt solution, and drying the lithium salt solution to obtain the lithium ion battery negative electrode. The process step is simple, the device requirement is low, the operability is high, the irreversible capacity loss of a battery can be effectively reduced, the energy density of the battery is enhanced, and the preparation method can be completely applied to industrial production of the lithium ion battery at a large scale.

Description

technical field [0001] The invention relates to the technical field of manufacturing lithium-ion batteries, in particular to a method for preparing negative electrodes of lithium-ion batteries that reduces irreversible capacity loss. Background technique [0002] At present, in the manufacturing process of lithium-ion batteries, the positive and negative plates are directly assembled together through the separator, and irreversible capacity loss will inevitably occur after liquid injection and activation. [0003] The existing technical solutions regard the irreversible capacity loss of lithium-ion batteries as an inherent property of lithium-ion batteries. By forming an SEI film, part of the capacity of the battery is lost, which increases the irreversible capacity of the first charge and discharge, which seriously affects the battery energy. of full play. At present, a large number of studies have shown that the SEI film formed on the surface of the negative electrode is ...

AI Technical Summary

Problems solved by technology

[0005] The present invention is to solve the problem that the negative electrode of the lithium ion battery in the prior art will increase the irreversible capacity when it is first charged and discharged, which will affect the full play of battery energy, and provides a preparation method for the negative electrode of the lithium ion battery that reduces the loss of irreversible capacity. The present invention The preparation method of the method has simple process steps, low requirements on equipment, strong operability, can effectively reduce the irreversible capacity loss of the battery, improve the energy density of the battery, and can be used in the industrial production of lithium-ion batteries on a large scale.