Method for predicting cycle life of lithium ion battery

Abstract

The invention relates to the technical field of lithium ion battery cycle life prediction, in particular to a lithium ion battery cycle life prediction method, which comprises the following steps of: installing a pressure sensor on the surface of a battery to be evaluated, applying initial pre-tightening force to the battery, and recording signal data of the battery cycle test pressure sensor; performing a short-term cycle test of a certain cycle number on the battery to be evaluated, recording the discharge capacity under different cycle numbers, and calculating the capacity retention ratio; extracting pressure sensor data corresponding to a fully charged state in each cycle test; and performing fitting calculation according to the cycle index, the discharge capacity and the voltage data of the pressure sensor, and predicting the cycle life of the battery. According to the method, expensive and precise testing equipment and complex theoretical calculation are not needed, the cycle life of the lithium ion battery can be rapidly predicted through short-term cycle testing, and time and resource waste generated by conventional testing can be greatly reduced.

Description

technical field [0001] The invention relates to the technical field of prediction of lithium ion battery cycle life, in particular to a prediction method of lithium ion battery cycle life. Background technique [0002] Lithium-ion batteries have been widely used in various fields because of their high energy density, small self-discharge, no memory effect, and long cycle life. The performance of lithium-ion batteries can be generally divided into two categories, one is electrical performance, the other is safety performance, and cycle life is one of the key indicators for evaluating battery electrical performance. For lithium-ion batteries, it is generally considered that when the available capacity of the battery decays to 80% of the initial capacity or rated capacity, it is the end of life. Lithium-ion batteries will undergo many complex physical and chemical reactions during the charge-discharge cycle, so the factors affecting the cycle life of lithium-ion batteries are ...

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Problems solved by technology

[0006] The present invention aims at the disadvantages of long cycle life evaluation cycle, complex model, and large deviation between life prediction value and actual measurement value in the prior art, and provides a rapid prediction method for cycle life of lithium-ion batteries. The cycle life evaluation cycle is short and the experimental results are accurate. , reduce test cost and waste of resources

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