Pre-charging method for lithium ion battery

Abstract

The invention discloses a pre-charging method for a lithium ion battery. The positive electrode active material of the lithium ion battery is a nickel-cobalt-aluminum material, and the pre-charging method comprises a stage type charging step and a constant-voltage charging step in sequence, wherein the stage type charging step comprises a first charging step and a second charging step in sequence; the current in the first charging step is lower than that in the second charging step; and the pre-charging electric quantity in the first charging step is 20-40% of the total electric quantity of the lithium ion battery. By adoption of the pre-charging method, a cell can achieve equivalent or even better electrical performance as the cell which adopts a conventional low-current long-term pre-charging process; and meanwhile, the pre-charging time is shortened, and production efficiency is improved.

Description

[0001] 【Technical field】 [0002] The invention relates to a lithium ion battery precharging method. [0003] 【Background technique】 [0004] At present, the application of lithium-ion batteries is becoming more and more widespread, and the demand for batteries is increasing. For battery manufacturers, on the one hand, it is necessary to improve production efficiency to meet market needs. . With the mechanization of production in the lithium battery industry, the pre-charging process has become an important link that currently restricts production speed and product quality. [0005] For lithium-ion batteries, when pre-charging is the first charge, due to electrochemical reactions, a passivation layer covering the graphite surface will inevitably be formed on the phase interface between the graphite negative electrode and the electrolyte, and this thin layer is the solid electrolyte. Interface (solid electrolyte interface) or SEI film. When precharging the lithium-ion battery...

AI Technical Summary

Problems solved by technology

The electrochemical reaction rate of the material is slow at room temperature, resulting in poor high-current charge and discharge performance of the material. Most studies on this material use low-rate charge-discharge, and the low rate will seriously affect the application of this system material. , so pre-charging still adopts the traditional lithium cobalt oxide pre-charging method, that is, charging with a small current for a long time, which has become an important link that restricts the production efficiency and product performance of this material system.

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