Lithium battery fires pose a significant threat to life and property. Prompt fire suppression intervention is crucial to suppress the development of such fires. To investigate the effectiveness of various common handheld fire extinguishers on lithium iron phosphate battery fires, we constructed an experimental platform for fire suppression in the event of thermal runaway in lithium batteries. Using 60 Ah lithium iron phosphate batteries as the experimental subjects, we selected ten extinguishing agents including water, water mist, dry powder, heptafluoropropane, carbon dioxide, water-based, 3% aqueous film-forming foam, perfluorohexanone, hydrogel, and liquid nitrogen. We conducted comparative experiments on the fire suppression efficiency of these agents for 60 Ah lithium iron phosphate battery fires. The study showed that: A 20-s discharge of water, dry powder, carbon dioxide, and 3% aqueous film-forming foam could not effectively prevent the re-ignition of thermally runaway batteries. Furthermore, a 20-s discharge of water mist, heptafluoropropane, water-based, and perfluorohexanone could not completely halt the spread of thermal runaway behavior, with adjacent batteries showing varying degrees of thermal runaway signs. Compared to the other eight extinguishing agents, liquid nitrogen and hydrogel demonstrated the best fire suppression effects. After a 20-s discharge of liquid nitrogen and hydrogel, the thermally affected battery did not re-ignite, and adjacent batteries showed no signs of thermal runaway. Continuous 20-s nitrogen injection reduced the surface temperature of the thermally runaway battery to − 118°C, doubling the cooling rate compared to hydrogel. Additionally, liquid nitrogen reduced the CO concentration in the experimental chamber from 724 to 232 ppm, thereby reducing the explosion risk of flammable gases. This study serves as a reference for selecting handheld extinguishing agents for lithium battery fires.
