Thermal runaway (TR) of a battery pack's elementary accumulator is a key factor that can lead to various safety issues, such as fires or explosions, involving both property and people. Several safety devices can prevent and/or mitigate the consequences of thermal runaway, including the PTC (Positive Temperature Coefficient) to limit short-circuit current, the CID (Current Interrupt Device) to disconnect the external electrical terminals from the internal active elements, and the Safety Vent for cell depressurization. Internal gas pressure is the main triggering factor. However, since the gas quantity strongly depends on the chemistry involved, these safety devices should be optimized for future battery generations.

In this PhD thesis, we will develop a methodology for sizing these safety devices through numerical simulations, incorporating all characterizations from the material scale to abusive cell testing. This research will therefore focus on both numerical and experimental aspects in parallel, in collaboration with other laboratories in our department