(a) Schematic illustration showing the design of an ultrafast thermal responsive electrolyte to prevent thermal runaway in lithium metal battery. (b) Images showing the solidification of TDT electrolyte by polymerization occurs within seconds at 140 °C. (c) Schematic illustration showing the determining factors of polymerization kinetics. (d) Cycling stability of LFP||Li cells with TDT and EDV electrolytes under different temperatures at 0.3 C. (e) Voltage-time curves of LFP||Li cells with TDT and EDV electrolytes at temperature below and above the melting point of separator. (f) Temperature-time curves of LFP||Li pouch cells with TDT and EDV electrolytes of accelerating rate calorimeter tests. TDT electrolyte shows no obvious heat release during the test, while the temperature of EDV electrolyte exceeds 1000 °C. Adapted with permission from Ref. [5].