Experimental study on the perfluorocarbons solution as fire extinguishing agent for thermal runaway in ternary lithium-ion batteries

The thermal runaway and its propagation in lithium-ion batteries represent the core risk of major fire accidents in energy storage systems. However, preventive and control measures addressing this issue still face severe challenges and have not been satisfactorily resolved. Through a series of experiments, this study conducted a detailed analysis of thermal runaway and its propagation in ternary lithium-ion batteries and innovatively proposed a novel fire extinguishing agent strategy based on perfluorocarbons, with a comparative analysis conducted against water. To deeply explore the mechanisms of thermal runaway and its propagation in lithium-ion batteries, accelerating rate calorimeter was used to analyze individual cell, and experiments on thermal runaway propagation were conducted. By adjusting the ratio of perfluorocarbons, the optimal ratio of the perfluorocarbon solution was determined and applied to cell assembly fires, further exploring its internal mechanism for inhibiting thermal runaway. The results indicate that the self-heating temperature and thermal runaway trigger temperature of 60 % SOC cell are 143.8 °C and 171.3 °C, respectively. The time for thermal runaway propagation between individual cells is extremely short, at only 6 s, with a maximum temperature reaching 795.1 °C. The proposed perfluorocarbon solution effectively suppresses thermal runaway fires, with a maximum cooling power approximately 1.1 times that of water, effectively dispersing the substantial heat. This study provides new ideas and methods for the design of fire extinguishing agents for lithium-ion batteries and holds significant guidance for the safety prevention and control of energy storage systems.