Versatile multiphysics model for thermal runaway estimation of a lithium‐ion battery

This study proposes a fast yet accurate multiphysics model for a lithium-ion battery (LIB) that estimates multiphysics responses under operational and abuse conditions. The proposed multiphysics model couples a novel electrochemical model and a thermodynamic-chemical model. The electrochemical model modifies a conventional streamlined model by accounting for the state of charge dependency. The thermodynamic-chemical model accounts for entropic, ohmic, and chemical reaction heating originating from thermal runaway, thereby replicating the chemical reaction of the main components in a LIB under abuse conditions. The proposed multiphysics model was calibrated through intensive experiments under operational and thermal abuse conditions. A comprehensive analysis revealed that the proposed model accurately estimated the electrochemical-thermal characteristics of both cells, confirming the accuracy and robustness. Moreover, the proposed method is seven to eight times faster than a pseudo-two-dimensional model, implying that the proposed model is effective for elucidating multiphysics thermal runaway phenomena in a three-dimensional LIB domain. Hence, the proposed model replicates thermal propagation inside a cell under electric abuse conditions. The versatility of the proposed fast yet accurate multiphysics model of LIBs was demonstrated with applications of an optimal cell design and a battery thermal management system.