Battery health assessment and recuperation play a crucial role in the utilization of second-life Li-ion batteries. However, due to ambiguous aging mechanisms and lack of correlations between the recovery effects and operational states, it is challenging to accurately estimate battery health and devise a clear strategy for cell rejuvenation. This paper presents aging and reconditioning experiments of 62 commercial high-energy type lithium iron phosphate (LFP) cells, which supplement existing datasets of high-power LFP cells. The relatively large-scale data allow us to use machine learning models to predict cycle life and identify important indicators of recoverable capacity. Considering cell-to-cell inconsistencies, an average test error of $16.84\% \pm 1.87\%$ (mean absolute percentage error) for cycle life prediction is achieved by gradient boosting regressor given information from the first 80 cycles. In addition, it is found that some of the recoverable lost capacity is attributed to the lateral lithium non-uniformity within the electrodes. An equivalent circuit model is built and experimentally validated to demonstrate how such non-uniformity can be accumulated, and how it can give rise to recoverable capacity loss. SHapley Additive exPlanations (SHAP) analysis also reveals that battery operation history significantly affects the capacity recovery.

通过62个商用高能型磷酸铁锂（LFP）电池的老化和重整实验，该论文使用机器学习模型预测电池寿命，并识别可恢复能力的重要指标，还发现了侧向锂非均匀性对可恢复容量损失的贡献，并通过等效电路模型和实验证明了锂非均匀性如何积累并导致可恢复容量损失，SHapley Additive exPlanations（SHAP）分析揭示了电池操作历史对容量恢复的显著影响。

采用数据分析和等值电路建模技术对老化锂离子电池进行健康诊断和恢复