Formation process capable of reducing self discharge of lithium ion battery

Abstract

The invention belongs to the field of lithium ion batteries and particularly discloses a formation process capable of reducing the self discharge of a lithium ion battery, which can be used for solving the problem of self discharge of an existing lithium ion battery. The invention further provides a formation process capable of reducing the self discharge of a lithium ion battery, which can be used for effectively reducing the self discharge rate of the lithium ion battery. The formation process comprises the following steps: 1) loading a to-be-formed battery into a tray, and loading the tray to a formation cabinet; 2) charging the battery loaded to the formation cabinet with low current by use of a computer; 3) transferring the charged battery into a 45-DEG C environment for storage, then transferring the charged battery into a normal-temperature environment, and standing for about 12h until the temperature of the battery is approximate to room temperature of 23-27 DEG C; 4) performing a process of loading the room-temperature battery, which is cooled to the room temperature, into the formation cabinet once again and conveying the room-temperature battery, namely hibernating for 5min, then charging to 4.2V by use of a 0.2C constant current, keeping the voltage constant until achieving a 4.2V voltage and a 22mA cut-off current, finally hibernating for 5min, fully activating the battery, and then transferring to a next process; and 5) calculating the self discharge of the battery.

Description

technical field [0001] The invention belongs to the field of lithium-ion batteries, in particular to a formation process for reducing the self-discharge of lithium-ion batteries. Background technique [0002] Formation is an important process in the production process of lithium batteries. During formation, a passivation layer is formed on the surface of the negative electrode, that is, a solid electrolyte interface film (SEI film). The quality of the SEI film directly affects the cycle life, stability, self- Electrochemical properties such as discharge and safety meet the requirements of "maintenance-free" sealing for secondary batteries, but SEI films formed by different chemical formation processes are different, and there are also great differences in the impact on battery performance. The traditional low-current pre-charging method is conducive to the formation of a stable SEI film, but long-term low-current charging will lead to an increase in the resistance of the for...

AI Technical Summary

Problems solved by technology

[0004] The invention overcomes the deficiencies in the prior art, solves the current self-discharge problem of lithium-ion batteries, and provides a formation process for reducing the self-discharge of lithium-ion batteries that can effectively reduce the self-discharge rate of lithium-ion batteries