Cell case expansion is analyzed as an early mechanical indicator of thermal runaway in lithium‑ion batteries. Rapid gas generation during SEI breakdown and separator melting increases internal pressure before vent opening, deforming the cell and stressing module structures. The session presents tailored heating setups and force‑displacement measurements that capture expansion dynamics under moderate and fast heating. Differences in venting behavior, pressure peaks, expansion rates, and released gas volumes are compared, providing essential data for pack design, warning thresholds, and configurations capable of tolerating the mechanical loads of thermal runaway.
