Non-destructive characterization of structural deformation and electrochemical degradation in retired prismatic lithium-ion batteries from electric vehicles
摘要
A comprehensive understanding of the degradation mechanisms of retired batteries from electric vehicle is prerequisite for their second-life utilization. However, most existing aging studies center on pouch and cylindrical cells, the findings of which cannot be directly applied to large-capacity prismatic batteries due to distinct structural differences. To address this, this study conducts a systematic investigation on authentic large-format retired electric vehicle batteries by employing multi-modal non-destructive testing techniques to bridge mechanical deformation and electrochemical aging characteristics. Specifically, X-ray computed tomography was utilized to quantify the volumetric evolution of the battery casing, jelly roll, and internal delamination, while ultrasonic techniques were employed to map the internal gas distribution. By correlating these structural parameters with electrochemical impedance spectroscopy and incremental capacity analysis, the coupling mechanism between mechanical deformation and electrochemical performance degradation was thoroughly explored. This study provides insights into the interplay between mechanical and electrochemical aging in prismatic batteries. The findings offer a useful reference for the health assessment of retired batteries and may provide helpful implications for the structural optimization of future battery designs.
