Formation method of lithium ion battery

Abstract

The invention provides a formation method of a lithium ion battery. A negative electrode active substance of the lithium ion battery is a graphite material; the electrolyte of the lithium ion batterycomprises lithium salt, an organic solvent and an additive, the organic solvent comprises ethylene carbonate, dimethyl carbonate and propylene carbonate, the additive comprises 1, 2-trifluoroacetic acid ethyl ethane, dimethyl sulfoxide and anisole, and the formation method comprises: injecting a first electrolyte accounting for 45-50 vol% of the total amount of the electrolyte, wherein the organicsolvent of the first electrolyte is ethylene carbonate, the additive is 1, 2-trifluoroacetic acid ethyl ethane, and the content of the 1, 2-trifluoroacetic acid ethyl ethane is 8-12% by volume; the organic solvent of the second electrolyte comprises propylene carbonate and dimethyl carbonate, the additives are dimethyl sulfoxide and anisole, and the content of dimethyl sulfoxide is 3.6-4.0% by volume and the content of the anisole is 0.15%-0.3% by volume; and performing formation to obtain the battery.

Description

technical field [0001] The invention relates to a method for forming a lithium ion battery. Background technique [0002] The high-temperature stability of lithium-ion batteries is one of the safety performances of balancing lithium-ion batteries, and the choice of electrolyte is the primary factor affecting high-temperature safety. As a cyclic ester, propylene carbonate has good performance at high temperatures. As a high-temperature The use of electrolyte has good safety performance, but when graphite negative electrode is used as the negative electrode, the branched chain of propylene carbonate will be inserted into the interlayer of graphite material, resulting in interfacial reaction between the electrolyte and the negative electrode, thus affecting the cycle life of the battery. Especially in a high-temperature environment, the impact on the lifespan is more obvious. Therefore, it is necessary to provide a solution that can overcome this defect. Contents of the inven...

AI Technical Summary

Problems solved by technology

[0002] The high-temperature stability of lithium-ion batteries is one of the safety performances of balancing lithium-ion batteries, and the choice of electrolyte is the primary factor affecting high-temperature safety. As a cyclic ester, propylene carbonate has good performance at high temperatures. As a high-temperature The use of electrolyte has good safety performance, but when graphite negative electrode is used as the negative electrode, the branched chain of propylene carbonate will be inserted into the interlayer of graphite material, resulting in interfacial reaction between the electrolyte and the negative electrode, thus affecting the cycle life of the battery. Especially in high temperature environment, the impact on life is more obvious, therefore, it is necessary to provide a solution that can overcome this defect