A comprehensive review of thermal runaway and thermal runaway propagation modelling approaches in lithium-ion batteries

The rapid shift to electric and hybrid vehicles has intensified the focus on Li-ion battery safety, especially regarding thermal runaway (TR) and its propagation (TRP). This comprehensive review examines the state-of-the-art in TR and TRP modelling approaches, aiming to improve safety and meet evolving standards. TR models typically use detailed Arrhenius-based reaction kinetics or simplified alternatives, with a strong emphasis on accurately capturing the highest energy release phase - chemical cross-talk. TRP models expand this to module and pack levels, incorporating heat transfer, venting, and spatial discretisation. The review summarises key methodologies, outlining their strengths, limitations, and areas for improvement. Visual aids, including TR and TRP modelling diagrams, help clarify complex mechanisms. Major findings highlight the dominance of chemical cross-talk in TR and the importance of heat conduction in TRP for pouch and prismatic cells. Future research should refine venting models to better capture convection effects, and consider variations in thermal properties, initial/boundary conditions, and cell ageing. Advancements in these areas can guide the development of more effective pack-level mitigation strategies, ultimately enhancing the safety and reliability of Li-ion batteries.