Fire-resistant and mechanically-robust phosphorus-doped MoS₂/epoxy composite as barrier of the thermal runaway propagation of lithium-ion batteries

Thermal runaway propagation (TRP) is an utmost safety issue in battery modules owing to its derivative accidents of fire or explosion. This study develops a novel flame-retardant epoxy resin (EP) board to prevent the battery TRP. The phosphorus doped MoS₂ nanowires (PR-MoS₂) is designed and incorporated into EP matrix to acquire EP/3.0 PR-MoS₂ composite. The composite shows 159.4 % increase in char yield, 56.7 % decrease in peak heat release rate, 56.6 % reduction in peak CO production rate. By using EP/PR-MoS₂-3 (EP/3.0 PR-MoS₂ composite with thickness of 3 mm) between 103450-pouch cells, TRP can be effectively stopped. Meanwhile, the temperature of surviving battery remains below 100 °C. Of note, the minimum changes in internal crystal structure, chemical composition and electrochemical characteristics are discerned for the surviving battery. This research will offer inspirations for the design of TRP suppression materials, guaranteeing the safety the battery.