Method for predicating cycle life of lithium ion battery

Abstract

The invention relates to a method for predicating the cycle life of a lithium ion battery. The method comprises the following steps of performing batch-type cycle test on a to-be-evaluated battery in a to-be-evaluated cycle condition, and recording an accumulated cycle index and cycle volume conservation rate of the battery; transferring the battery not subjected to the batch-type cycle test and the battery subjected to the batch-type cycle test to an accelerating rate calorimeter, testing the thermal discharge in a charging process, recording temperature change data of the battery in the charging process, and calculating the temperature rise rate of the battery relative to an initial state; performing data fitting and calculation according to the accumulated cycle index and cycle volume conservation rate of the battery and predicating the cycle life of the battery. Compared with a conventional cycle test, the method provided by the invention has the advantages of greatly shortening the test period and avoiding energy consumption and resource waste generated by long-term test; in addition, data fitting is performed on the basis of short-term measured data, so that compared with pure-theory calculation and an empirical model, the method has the advantages of better universality and higher predicating accuracy.

Description

technical field [0001] The invention belongs to the technical field of lithium-ion battery cycle life testing, and in particular relates to a method for predicting the cycle life of lithium-ion batteries. Background technique [0002] Due to its high energy density, high working voltage, long cycle life and low self-discharge rate, lithium-ion batteries have attracted more and more people's attention, and their application range has been expanding. , Cameras and other general application fields, expanded to electric vehicles, aerospace and energy storage and so on. [0003] In the performance test of lithium-ion batteries, a test that is indispensable and everyone is very concerned about is the cycle life test, including normal temperature cycle, low temperature cycle, high temperature cycle test, etc. The cycle life test is usually in all battery performance tests. It is the longest one, and with the development and application of long-life batteries, the time required for...

AI Technical Summary

Problems solved by technology

[0003] In the performance test of lithium-ion batteries, a test that is indispensable and everyone is very concerned about is the cycle life test, including normal temperature cycle, low temperature cycle, high temperature cycle test, etc. The cycle life test is usually in all battery performance tests. The longest time-consuming item, and with the development and application of long-life batteries, the time required for their routine cycle life tests will be extended

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