A Review on Mitigating Thermal Runaway Propagation in Battery Packs: from Mechanisms to Modeling and Design Optimization

Abstract

Thermal runaway (TR) in modern lithium-ion battery packs is a critical safety concern due to its potential to cause fires or explosions. When a single cell experiences TR, the intense heat and exothermic reactions can rapidly propagate to neighboring cells, leading to thermal runaway propagation (TRP) at the module or pack level. This review provides a comprehensive examination of TR and TRP, spanning from fundamental mechanisms through advanced modeling techniques to practical mitigation measures and pack-level design optimization strategies. We first delineate the chemical and thermal mechanisms that initiate TR and govern cell-to-cell propagation. We then review state-of-the-art modeling methods, from reduced-order analytical models to detailed 3D multiphysics simulations, as well as emerging data-driven models that predict the onset and propagation of TR events. The strengths and limitations of these modeling approaches are compared in the context of safety prediction. Finally, we discuss current TRP mitigation strategies and emphasize safety-conscious design optimization for battery packs. By integrating improved thermal management, protective materials, and optimized pack architecture, the review highlights how design optimization can minimize propagation risks. Through this holistic approach, the article offers insights to guide researchers in developing next-generation battery packs with enhanced safety and resilience against TR.