Abstract: In order to explore the influence of pressure change on thermal runaway suppression effect of 150 Ah large capacity ternary lithium-ion battery during storage and use of bottle group fine water mist fire extinguishing device, a combustion suppression experiment platform was built and thermal runaway suppression experiment for lithium-ion battery was carried out. The results show that under the experimental conditions in this paper, the greater the water mist pressure, the shorter the time needed to restrain thermal runaway. There is reignition phenomenon after 1.2 MPa fine water mist extinguishes lithium-ion battery open flame. Under the condition of successfully extinguishing lithium-ion battery thermal runaway open flame, 10 MPa fine water mist consumes the least amount of water. Pressure attenuation will reduce the extinguishing effect of bottle group water mist. This experiment can provide reference for system selection, operation and maintenance of fine water mist extinguishing device to suppress thermal runaway of large capacity ternary lithium-ion battery.

Key words: lithium-ion battery, thermal runaway, water mist, pressure, cooling efficiency