Life decay characteristics identification method of retired power batteries based on inverse power law model of accelerated life test

Abstract

In order to reduce the sorting complexity of retired power batteries, the life decay characteristics identification method of power battery module based on the accelerated life test is proposed in the paper. Firstly, the influence of different parameters (environmental temperature, charge–discharge depth, charge–discharge rate, etc.) on the life decay of single battery is analyzed according to the historical data of retired power batteries. The main parameters affecting the life decay of power battery are determined. Secondly, the correlation characteristic function between terminal voltage, state of charge (SOC) of single battery and state of health (SOH) of battery module is established. The accelerated stress conditions suitable for retired power battery module is selected for accelerated life test. Finally, the attenuation characteristics of retired battery module are characterized by accelerated life test, which provided theoretical support for the rapid and accurate echelon utilization of power batteries.

Keywords

• Battery module
• Life loss
• Accelerated life test
• Decay characteristics