Cycle life prediction and match detection in retired electric vehicle batteries
(1. School of Metallurgy and Environment, Central South University, Changsha 410083, China;
2. Electric Power Research Institute, Henan Electric Power Corporation, Zhengzhou 450052, China)
2. Electric Power Research Institute, Henan Electric Power Corporation, Zhengzhou 450052, China)
Abstract: The lifespan models of commercial 18650-type lithium ion batteries (nominal capacity of 1150 mA·h) were presented. The lifespan was extrapolated based on this model. The results indicate that the relationship of capacity retention and cycle number can be expressed by Gaussian function. The selecting function and optimal precision were verified through actual match detection and a range of alternating current impedance testing. The cycle life model with high precision (>99%) is beneficial to shortening the prediction time and cutting the prediction cost.
Key words: retired electric vehicle battery; life prediction model; match detection; electrochemical impedance spectroscopy; equivalent circuit