Safety issue of lithium-ion batteries (LIBs) is always a concern. We have studied the inhabitation on thermal runaway (TR) and propagation of 18,650 LIBs in an enclosed space systematically. LIBs at 70% state of charge are chosen for testing. Four fire extinguishing agents are applied on LIB arrays for 20 s, and the inhibiting effects are different. The cooling efficiency varies with the surface temperatures of LIBs. Water spray has the highest cooling efficiency and inhibits the TR propagation among LIB arrays successfully. Three LIBs undergo TR for the releasing of ABC ultrafine dry powder. BC ultrafine dry powder and Novec 1230 are failed to inhibit the TR propagation. Nevertheless, Novec 1230 shows the best on inhibiting fire occurring and the generation of toxic gas. Generally, this study provides valuable information for the choice of fire extinguishing agents.

Clean gas fire suppressants with high efficiency are widely applied. This paper provides a systematic review of the research advances in the novel environmentally friendly suppressant, C₆F₁₂O. Considering the principle of screening fire suppressants, the physical and chemical properties of C₆F₁₂O are presented first. Specifically, research on the measurement of the thermodynamic parameters, toxicity, corrosion, environmental compatibility and dispersion characteristics are summarized, revealing that the poor dispersibility, corrosion of the hydrolysates (perfluoropropionic acid), corrosion and toxicity of thermal breakdown products such as HF and COF₂ and environmentally unfriendly products such as perfluorocarbons should be paid more attention. Three main synthesis routes of C₆F₁₂O are also introduced in view of its promising prospects for application. Furthermore, the fire extinguishing efficiency of C₆F₁₂O has been fully investigated in both a laboratory burner scale and full-scale fire extinguishing experiment, the results of which show that the minimum extinguishing volume concentration of C₆F₁₂O is lower than HFCs, but the mass concentration is much higher. Although C₆F₁₂O has shown satisfactory fire extinguishing performance in various fire protection scenarios, fire enhancement phenomenon and the large production of HF have been observed during fire extinguishment. Finally, the fire extinguishing mechanism of C₆F₁₂O has been discussed. The flame suppression effect of C₆F₁₂O, combustion enhancement phenomenon and the influence of water in the reaction zone have been revealed. This review fully evaluates C₆F₁₂O, in hope that it will provide a reference for follow-up research and the development of a halon replacement.