Research on Smoke and Gas Venting Behaviors of Battery Thermal Runaway in Enclosed Battery Modules

The ejection of high-temperature smoke particles and gas during thermal runaway of lithium-ion batteries constitutes one of the critical causes of thermal propagation in new energy vehicles, posing a severe threat to occupant safety. Within an enclosed battery module, the accumulation of vented smoke and gases due to inadequate venting promotes the propagation of thermal runaway, resulting in a chain reaction among adjacent cells. In this study, a thermal runaway venting channel model is developed for enclosed battery modules, with vent ports configured separately on the side and end surfaces of the module gas passage. A multiphase gas-solid coupling thermal runaway ejection model that incorporates both gas and particulate matter is established to compare the effects of the two venting cases on thermal propagation and to analyze the effect of active ventilation on the smoke extraction performance. The results demonstrate that vent ports arranged at the module end exhibit superior venting performance in the absence of external ventilation, whereas side-mounted vent ports achieve the optimal venting efficiency when active ventilation is introduced.