Self-discharge screening method of lithium ion batteries

Abstract

The invention discloses a self-discharge screening method of lithium ion batteries. The self-discharge screening method of the lithium ion batteries comprises the following steps: (1) pretreating, namely, testing the voltages of full (half)-electricity lithium batteries put before and after by adopting a voltage internal resistance tester, recording the voltage data value OCV1 after putting and the voltage data value OCV2 after putting again, determining the critical value U0 of the voltage level at the same period of OCV2, calculating to obtain that batteries with OCV2 smaller than U0 are serious self-discharged batteries, and removing the serious self-discharged batteries; (2) screening the self-discharged batteries according to the voltage difference of the pretreated full (half)-electricity lithium batteries after putting and putting again by adopting a'3 Sigma' circulation removing method. The self-discharge screening method of the lithium ion batteries can be used for calculating for lithium ion battery production manufacturers in batches, and the production efficiency and the product shipment quality are improved greatly.

Description

technical field [0001] The invention relates to a lithium-ion battery self-discharge screening method, which is particularly suitable for self-discharge selection of lithium-ion batteries in a full (half) electric state. Background technique [0002] Lithium batteries have the characteristics of high specific energy, low self-discharge rate, good high and low temperature performance, long charge and discharge life, and no memory effect. They are currently widely used in notebook computers, video cameras, digital cameras, personal digital assistants (PDAs), mobile communications In terminal products and electric tools, many products need to use multiple cells in series or in parallel to achieve higher output voltage and capacity. There are differences in performance such as power efficiency, and the screening of single cells with basically the same performance is the key link in the formation of battery packs. The screening of single self-discharge batteries is very important...

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Problems solved by technology

[0002] Lithium batteries have the characteristics of high specific energy, low self-discharge rate, good high and low temperature performance, long charge and discharge life, and no memory effect. They are currently widely used in notebook computers, video cameras, digital cameras, personal digital assistants (PDAs), mobile communications In terminal products and electric tools, many products need to use multiple cells in series or in parallel to achieve higher output voltage and capacity. There are differences in performance such as power efficiency, and the screening of single cells with basically the same performance is the key link in the formation of battery packs. The screening of single self-discharge batteries is very important. A simple and accurate self-discharge screening method is very important for lithium battery manufacturers. It is said that it can reduce the risk of shipment and improve product quality, but the current selection method for lithium-ion self-discharge is complicated and has a high rate of misjudgment.

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