Rapid temperature-responsive thermal regulator for safety management of battery modules

Effective thermal safety management relies on the thermal conductivity of interlayer materials, yet current designs lack the needed responsiveness for both performance and safety. Here we design a thermal-switching material with high switching ratio from thermal conduction to thermal insulation state to address this predicament. The designed thermal-switching material exhibits a wide temperature range for heat conduction (1.33 W m−1 K−1 at room temperature) and can transform to an adiabatic state within 30 s (0.1 W m−1 K−1 at around 100 °C) when heated. When applied as cell-to-cell interlayers for a module with four 50 Ah nickel–cobalt–manganese lithium-ion cells, the material not only ensures a uniform temperature distribution under normal working conditions, but more importantly prevents 80% of the heat transmission from thermal runaway, effectively avoiding catastrophic battery explosion. We believe that this thermally responsive material design will ensure safety and high performance throughout the lifespan of high-energy-density battery modules. Smart temperature-responsive materials could enhance battery thermal safety management; however, current designs lack the necessary responsiveness for both performance and safety. Here the authors demonstrate a material that swiftly transitions from thermal transmission to isolation during thermal runaway in battery modules, thereby ensuring battery safety.