Experimental and numerical investigation of various thermal barrier materials for mitigating thermal runaway propagation in lithium-ion battery modules

Thermal runaway (TR) and its propagation (TRP) in large-capacity lithium-ion batteries (LIBs) have become critical obstacles to their safe application. The propagation inhibition capabilities of four thermal barrier materials (TBMs), including silicone foam (SF), composite phase change material (CPCM), mica-derived material (MDM), and ceramic fibre aerogel (CFA), within a 151 Ah LIB module were investigated. Experimental results demonstrate that CFA successfully inhibits TRP, limiting the maximum surface temperature of the adjacent battery to 248.5 ℃, whereas SF, CPCM, and MDM, though failing to completely block propagation, all slow down the TRP process to varying degrees. Furthermore, a module-level coupled thermal diffusion barrier model was further developed, incorporating internal exothermic reaction kinetics, discrete-structure heat conduction, and equivalent flame radiation. Model validation yields relative errors ≤4% for TRP trigger time and ≤15% for peak battery surface temperature. These findings highlight that the principle of TRP suppression is essential to increase the energy threshold required for the downstream battery to initiate TR. Experimental data and theoretical foundations are provided for the thermal safety design of high-energy-density LIBs modules and the development of advanced thermal barrier technologies.