Electro-thermal model of a pouch cell battery considering thermal runaway

Abstract Li-ion batteries are increasingly expanding their fields of application: automotive, electronic devices, and residential are just a few demonstrations of that. One of the most critical problems with batteries is overheating, which can lead to thermal runaway and a battery fire. For these reasons, the need for an accurate multiphysics model is growing and consequently an electro-thermal model of a pouch cell battery, including thermal runaway reactions, is proposed. It involves a two-dimensional electrical model for the cell potential distribution, and a three-dimensional thermal model to describe the temperature field. The two models are coupled because parameters such as the overpotential resistance and the thermal runaway reactions are temperature-dependent. The electrical model is based on the charge conservation theory, coupled with the ohmic law equations. The thermal model is governed by the heat diffusion equation with total heat generation calculated as the sum of three different parts: ohmic, irreversible and reversible, while thermal runaway occurrence is governed by an Arrhenius equation. After a comparison with literature data, numerical results in terms of temperature are shown, demonstrating a significant temperature rise during the thermal runaway process.