Numerical and experimental characterization of nail penetration induced thermal runaway propagation in 21,700 lithium-ion batteries: Exploring the role of interstitial thermal barrier materials

Abstract

Thermal runaway (TR) in lithium-ion batteries (LIBs) involves a complicated multiphysics process with potentially catastrophic consequences, highlighting the importance of investigating effective prevention strategies. This study employs a lumped model integrating electrochemical and decomposition reaction kinetics to predict the evolution of the TR of LIBs triggered by axial nail penetration, validated by experimental tests. A computational fluid dynamics (CFD)-based turbulent flow model is further employed to simulate the thermal runaway propagation (TRP) behavior induced by high-temperature gases within the battery module. A parameterized analysis based on numerical simulation is conducted to quantify the impact of thermal insulation material properties on thermal diffusion and heat accumulation within the module. The results indicate that damage to the battery vent significantly increases the risk of sidewall rupture during TR. The incorporation of thermal barriers is essential in the thermal design of battery modules to prevent heat transfer via convection from the thermal exhaust caused by sidewall rupture to adjacent cells. In addition, a reduction in the thermal diffusivity of the thermal barrier material is required to minimize thermal exchange between battery cells. By adopting insulating materials with thermal diffusivity lower than 0.3 mm²/s, the TRP of batteries can be mitigated under non-enclosed conditions. These findings contribute to improved battery safety and inform the development of more effective thermal protection measures and safety standards.