Method for evaluating high-temperature aging time of lithium ion battery

Abstract

The invention discloses a lithium ion battery high-temperature aging time evaluation method which comprises the following steps: 1) respectively adding Fe and Cu particles into absolute ethyl alcohol to obtain a Fe/alcohol mixture and a Cu/alcohol mixture; 2) taking a plurality of naked battery cells as a group, dividing each group of naked battery cells into three parts, performing Fe particle implantation on one part of naked battery cells, performing Cu particle implantation on the other part of naked battery cells, and performing no metal particle implantation on the rest part of naked battery cells; 3) taking the four groups of naked battery cells obtained in the same step 2), producing according to a process with different high-temperature aging time to obtain finished battery cells, and carrying out OCV test on the finished battery cells after capacity grading; and 4) processing and analyzing test data to obtain target high-temperature aging time T. According to the method, the Fe and Cu metal particles are implanted into the battery cell, so that the self-discharge screening rates of the metal implanted battery cell at different high-temperature aging times are compared, and the optimal high-temperature aging time is quickly and accurately obtained.

Description

technical field [0001] The present invention relates to lithium ion batteries, in particular to a method for evaluating high temperature aging time of lithium ion batteries. Background technique [0002] Lithium-ion batteries have many advantages such as high voltage, high specific capacity, environmental friendliness, and many cycles. They have been widely used in mobile phones, digital cameras, notebook computers, electric vehicles and other fields. [0003] There is an aging process in the lithium-ion battery manufacturing process. Aging is divided into normal temperature aging and high temperature aging. The purpose of aging is to stabilize the properties and composition of the SEI film formed after initial charging, while high temperature aging is mainly to shorten the aging time. Thus, the production efficiency is improved, and the high temperature aging can fully expose the bad phenomena of the battery. [0004] At present, the high-temperature aging time adopted by ...

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Problems solved by technology

[0004]At present, the high-temperature aging time adopted by various power battery enterprises is between 0-48h. If the aging time is too short, the aging effect will not be achieved, resulting in poor performance of the battery. Self-discharging defective batteries containing metal particles will flow into the market and cause electric vehicle fire problems; if the aging time at high temperature is too long, the battery production cycle will be prolonged, which is not conducive to reducing the battery life. manufacturing cost

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