Lithium battery cycle life prediction method

The invention discloses a lithium battery cycle life prediction method. The method comprises the following steps: S1, carrying out a plurality of charging and discharging tests on a lithium battery; s2, recording the variable quantity SOC of the SOC of the lithium battery every other time T; s3, calculating the discharge depth and the average rate of the lithium battery in each charge-discharge test according to the SOC; and S4, calculating the cycle life of the lithium battery according to the discharge depth and the average rate. Physical parameters in a current lithium battery cycle life model are difficult to obtain, a large amount of experimental data and long test time are needed in the parameter identification process, meanwhile, simulation of the lithium ion battery cycle effect is difficult to achieve, and the cost is high. On the basis, the invention provides a cycle life model prediction method of the lithium ion battery, a lithium battery cycle physical equation based on a fatigue theory and equiv