Application of a Chemical Kinetic Modeling Approach within a Fully Coupled Computational Fluid Dynamics Simulation of Battery Cells during Thermal Runaway

<div>The objective of the current study is to systematically evaluate the battery thermal runaway heat release rate through chemical kinetics and then study its effect on battery module and pack level. For this purpose, a chemistry solver has been developed, capable of simultaneously solving the thermal runaway kinetics in multiple battery cells with the cell-specific chemistry model and battery active material compositions. This developed solid body chemistry (SBC) solver assumes a homogeneous system in the specified geometrical selection. A 3D representation can be achieved by setting up multiple solver selections in one solid domain (battery cell) as the SBC solver is capable of handling multiple selections, chemistry models, and battery active material compositions. Further, the SBC solver is fully integrated in a commercial three-dimensional computational fluid dynamics (3D-CFD) code. Thus, enabling to simulate the real-life thermal runaway applications covering the battery module and battery pack including relevant physicochemical processes involved. In addition to the direct solution of the chemical kinetics, an alternative approach is proposed for pack-level thermal runaway simulations where kinetically extracted heat release rate is used. As demonstrated in the results and discussion, the SBC solver is able to accurately reproduce the initiation and propagation of thermal runaway on a cell level and provides significant insights when coupled with a 3D-CFD solver on a module- and pack-level simulations and thus understanding the real-life hazard scenarios in the battery safety management.</div>