Abstract: In order to quickly extinguish lithium?ion battery fires in the early stage, based on the fire detection tube material, water was selected as the extinguishing agent and a small fire extinguishing system of water based fire detection tube was set up. The effectiveness of the fire detection tube material in extinguishing lithium?ion battery fires was studied, and lithium?ion battery fire suppression experiments were conducted under different water consumption and driving pressure. The results show that the fire detection tube material can respond quickly after the battery thermal runaway is triggered, release extinguishing agents, suppress the gas production and combustion of the battery thermal runaway, and quickly cool the battery; The cooling capacity of the system is positively correlated with water consumption. As the water consumption increases, the maximum surface temperature and duration of high temperature of the battery greatly decrease. When the water consumption was 100 mL, a pressure of 0.5 MPa failed to ensure timely response of the system, resulting in an open flame in the battery after thermal runaway; As the driving pressure gradually increases, the droplets released by the system exhibit a significant sputtering phenomenon, which has a negative impact on the cooling efficiency of the system. When the driving pressure is 1 MPa, the cooling performance of the system is optimal. For fires caused by thermal runaway of battery modules, the fire detection tube material can quickly respond, release extinguishing agents to extinguish initial battery fires, and prevent the spread of thermal runaway of battery modules.

Key words: lithium?ion battery, thermal runaway, fire suppression, fire detection tube