Life Prediction Method of Power Battery for New Energy Vehicle

Abstract

Battery life is a key factor restricting the development of new energy vehicle manufacturing industry.Taking a LiMn₂O₄ power battery as an example, the life prediction method of power battery based on performance degradation data was studied. It is found that the capacity of the battery basically conforms to the decline trajectory of the power function, and the pseudo failure life of the battery is extrapolated by using the decline model. The distribution of pseudo failure life is studied, and the results are consistent with the fitting effect of Weibull distribution. Finally, the reliability of the battery is evaluated based on Weibull life distribution. This paper analyzes the influence of the actual cycle data on the prediction accuracy. The test results show that the life model and reliability evaluation method have high accuracy, and solve the problems of long life evaluation cycle and high cost of power battery.