The role of lithium-ion battery vent gas in thermal runaway propagation to adjacent modules in energy storage systems
Abstract
This study explores the role of Lithium-ion battery vent gases in module-to-module thermal runaway propagation in energy storage systems. The focus here is on propagation by direct convective heating from vent gas impingement. The results indicate that vent gases contribute to module-to-module propagation by preheating cells in adjacent modules. The results also show that designing cells with large safety vent size, which is related to vent jet speed, and large module gap height between the cells and the module top surface reduces the convective heat transfer caused by direct vent gas impingement during thermal runaway which can potentially reduce the risk of module-to-module propagation. For example, doubling the module gap height and reducing the venting velocity by 70% decreases the maximum heat flux transferred by the vent gas to the adjacent module by 59.6%. Consequently, the number of venting cells required to initiate thermal runaway in a cell within the neighboring module increases from 5 to 22. This finding demonstrates that these design modifications can significantly reduce the likelihood of module-to-module thermal runaway propagation by requiring a greater number of cell failures to initiate propagation. While increasing the vent opening and module gap height reduces wall heat flux but increases gas residence time within the module channel, highlighting a potential safety trade-off that needs further investigation. It is also shown that cells at different positions within a module experience distinct heating mechanisms due to successive venting events, where slow heating process tends to be more hazardous than rapid heating unless this rapid heating directly triggers thermal runaway. Additional heat transfer by vent gases outside the module channel may occur as these gases exit the module channel at high temperatures and velocities, indicating a potential risk for further thermal runaway propagation.
Publication Title
International Journal of Heat and Mass Transfer
Recommended Citation
Qatramez, A., Kurzawski, A., Hewson, J., Meehan, M., Foti, D., & Headley, A. (2026). The role of lithium-ion battery vent gas in thermal runaway propagation to adjacent modules in energy storage systems. International Journal of Heat and Mass Transfer, 271 https://doi.org/10.1016/j.ijheatmasstransfer.2026.129463
