Rapid prediction method for cycle life of lithium ion battery

Abstract

The invention discloses a rapid prediction method for the cycle life of a lithium ion battery. The method comprises the following steps of carrying out the charge and discharge performance test on a to-be-evaluated battery at different numbers of cycles, and recording a relation curve among the voltage, the capacity and the time of the battery during the charging process at different numbers of cycles; calculating the change delta C of the capacity of the battery when the voltage of the battery changes from 3.95V to 4.15V during the charging process at different numbers of cycles according tothe relation curve; according to the change delta C of the capacity and the test data on the numbers of cycles, conducting the fitting calculation and predicting the cycle life of the battery. Compared with the conventional cycle life test method, the above method is simple and feasible. The test period of the cycle life is greatly shortened. Compared with the pure theory calculation and the empirical model prediction, the method is better in universality. The actual test results of the method are better in consistency. The research and development speed of products is accelerated. The methodcan be widely applied to the field of new energy and the like.

Description

technical field [0001] The invention relates to the technical field of lithium-ion battery cycle life testing, in particular to a rapid prediction method for the cycle life of lithium-ion batteries. Background technique [0002] Lithium-ion batteries are widely used in mobile digital products due to their environmental friendliness, low pollution, long cycle life, and no memory effect, and are even used in electric vehicles as energy storage systems. Service life is an important indicator to measure battery performance. With the rapid development of battery technology, the cycle life of batteries in the field of electric vehicles has reached 2000 or even more than 2500 times. At present, the life test method widely used in the research and development, inspection and selection of lithium-ion batteries is to conduct cycle tests under certain working conditions. And energy consumption, but also lead to slow progress in product development. Therefore, if information related t...

AI Technical Summary

Problems solved by technology

[0003] Researchers have done a lot of research in the field of rapid test technology for the cycle life of lithium-ion batteries, and have obtained some accelerated test schemes, such as choosing fast charging and discharging conditions and testing in high temperature environments, etc., usually still need thousands of hours to complete. The test can be completed, but there is still a waste of resources

Therefore, shortening the cycle of life evaluation has become an urgent problem to be solved.

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