Numerical Modelling of Thermal Runaway for Li-Ion Battery Module For EV Applications

Emissions from conventional vehicles are one of the significant contributors to the environment pollution, so Electrical Vehicles (EV's) become an alternative for future transportation. The major challenge with the EV's is with their energy storage systems, i.e., lithium-ion batteries, which are extremely sensitive to working temperatures. High temperatures cause thermal runaway propagation to the adjacent cells and eventually lead to permanent failure of the battery pack. The present study proposes a new Phase Change Material (PCM) between the cells to avoid such unsafe thermal conditions. Ansys Fluent is used for the model validation for a Samsung 21700 Li-ion cylindrical battery module containing 63 cells with the configuration of 9P7S. The model parameters are calibrated by using the Accelerating Rate Calorimetry measurement data. The study reveals that in the absence of PCM, the peak temperature in the abuse cell reaches to 1040K, and thermal diffusion causes heat transfer to the neighboring cells. When the PCM is present, the cell volume average temperature is reduced by ~20% and the thermal runaway is delayed by 120 seconds. Hence, the present study demonstrates that introducing the PCM between the cells is one of the efficient thermal management techniques for Li-ion battery packs in EV's.