3D Thermal Simulation of Thermal Runaway Propagation in Lithium-Ion Battery Cell Stack: Review and Comparison of Modeling Approaches

Three empirical modeling approaches for the heat release during a lithium-ion battery cell thermal runaway (TR) are analyzed and compared with regard to their suitability for TR propagation simulation. Therefore, the experimental results of a battery cell stack experiment consisting of five prismatic lithium-ion batteries (>60 Ah) are compared to simulation results of a model that is built within the 3D-CFD framework of Simcenter Star-CCM+ ®. In contrast to previous studies, the proposed model takes into account detailed phenomena such as the formation of a gas layer between jelly roll and cell can due to electrolyte vaporization, which is crucial to reproduce experimental results. Only two of the three modeling approaches are suitable for TR propagation simulation of the cell stack experiment investigated in this study. These approaches either use time-dependent or spatially resolved temperature-dependent heat release rates. The proposed consideration of gas layer formation as well as the comparative analysis of the modeling approaches contribute to the improvement of TR propagation simulations and support engineers as well as researches to design a safer battery pack.