The continued electrification of the automotive sector is bringing the challenges of battery electric vehicles (BEVs) into focus, particularly in terms of fast charging capability, safety aspects and range. High-energy cells offer potential solutions to these challenges, but are associated with reduced thermal stability, which increases the risk of thermal runaway (TR) and thermal propagation (TP). TR can be triggered either by inherent cell defects or by abuse. To ensure the safety of battery cells while maximising energy density is a significant challenge.
To reduce development times and optimise integration, a numerical model is proposed that takes into account the thermal behaviour of the battery cell and the entire battery pack in the early phase of development. The aim is to develop a parameterised model that is both simple and adaptable for different cell chemistries, while providing essential parameters to accelerate the development of an optimised propagation system.
A three-dimensional heat propagation model is being developed using the commercially available software Ansys Fluent, based on a four-materialised Arrhenius equation that describes the thermal abuse mechanisms. In the first simulations, two cell chemistries, lithium cobalt oxide (LCO) and lithium iron phosphate (LFP), were analysed. The results of these initial simulations form the basis for the further development of the model, including the integration of additional materials and the expansion into a TP model, in order to enable a quick analysis of TP protection systems.