Abstract: How to effectively isolate the heat transfer between lithium-ion battery modules and suppress the thermal runaway propagation of lithium-ion batteries has always been a concern in the field of fire protection. In order to explore the inhibitory effect of thermal insulation materials on the thermal runaway propagation of lithium battery modules, this work built a battery thermal runaway experimental platform. Taking 75 Ah lithium iron phosphate battery as the experimental object, four thermal insulation materials, namely aerogel felt, ceramic fiber paper, mica board and glass fiber felt, were selected to study the inhibitory effect of thermal insulation materials in the process of thermal runaway propagation. The research results indicate that without insulation layer protection, thermal runaway will rapidly propagate between lithium battery modules, and flame superposition will further accelerate the propagation speed of thermal runaway; Four insulation materials with a thickness of 3 mm can successfully weaken the heat transfer between batteries and suppress the propagation of thermal runaway in lithium-ion batteries; In terms of thermal insulation performance, compared with glass fiber felt, mica board and ceramic fiber paper, the thermal insulation effect of aerogel felt increased by 16%, 23% and 35% respectively. This study can enrich the application of thermal insulation materials in the process of lithium battery fire prevention.

Key words: lithium-ion battery, thermal runaway, thermal insulation materials, flame propagation, inhibition effect