Abstract: Fires and explosive hazards of lithium-ion batteries resulted from thermal runaway (TRA) propagations presented threats on the public safety. In order to prevent large-scale hazard of battery systems, one effective method is TRA mitigation. In this work, epoxy resin board (ERB) was applied to mitigate the TRA propagation of prismatic battery modules. It was found that ERB can lower the highest temperature of the battery module, mitigate the TRA severity of the batteries, and avoid the generation of the jet flames. For the module with parallel electric connection, the average TRA propagation time was 198 s per battery number when 2 mm ERB was applied, which was 2.29 times compared to that without ERB. And it was extended to 5.57 times when 4 mm ERB was used. For the module with series electric connection, the average thermal runaway propagation time was extended to 2.09 times with 2 mm ERB applied. While TRA propagation was prevented when 4 mm ERB was used, which meant thermal runaway was more easily propagated in module with parallel connection than that with series connection, because of the additional joule heat caused by the formed electrical circuit.

Key words: lithium-ion batteries, thermal runaway, propagation, epoxy resin board, mitigatio