A framework for modeling mechanically induced thermal runaway in lithium-ion batteries

Battery safety is a paramount concern in the development of electric vehicles (EVs), as failures can lead to catastrophic consequences, including fires and explosions. Ensuring the reliability and robustness of lithium-ion cells under various conditions is essential for the widespread adoption of EVs. With the rapid global adoption of EVs, understanding how battery cells perform under extreme conditions such as mechanical or thermal abuse is crucial for ensuring safety. This study investigates the dynamic behavior of lithium-ion pouch cells under mechanical abuse conditions, focusing on improving safety measures in EV battery systems. Our research systematically examines the response of these cells at different states of charge (SOC), through controlled dynamic tests. These tests, which involve varying strain rates and punch geometries, offer significant insights into the mechanical thresholds that lead to cell failure. By analyzing the data, we gain a deeper understanding of the conditions that could trigger thermal runaway under mechanical abuse conditions such as EV crash, a critical safety concern in EV battery systems. The experimental setup and methodologies are presented in this paper, alongside key findings that highlight the importance of incorporating dynamic behavior which is more representative of conditions seen in EV mechanical abuse or crash scenarios. Multiphysics cell models that bring in the electro-thermo-mechanical response of the cell provide insights into battery behavior during mechanically induced internal shorting and help provide an understanding of thermal runaway risk. These findings contribute to the development of more resilient battery systems, enhancing the overall safety of electric vehicles in real-world scenarios.