Degradation of Lithium-Ion Batteries:Mechanisms and Models of Mechanical-Electrochemical Coupling
Upon charge-discharge cycling,lithium-ion batteries inevitably undergo capacity fading,which is a common and well-acknowledged phenomenon.However,the mechanisms behind this apparent performance degradation are inherently complex.In this review,the mechanical-electrochemical coupling degradation mechanisms of lithium-ion batteries in multi-scale,multi-field,and multi-process are comprehensively reviewed,starting from the particle scale to the electrode scale,with a specific focus on degradation in solid-state batteries.Furthermore,the degradation models used to describe the mechanical-electrochemical coupling degradation behavior of lithium-ion batteries are reviewed.It should be noted that due to the complexity of battery degradation mechanisms and the scarcity of externally measurable parameters,establishing degradation models is challenging,and there is still a considerable research gap.In light of this,a conceptual bidirectional degradation model that integrates physical models and data-driven models is proposed.Serving as links,internal variables with meaningful physical implications should be introduced to establish a comprehensive mapping of"mechanical behavior-internal variables-degradation behavior",to provide a novel approach for objectively and accurately describing and predicting battery degradation behavior.