Abstract: Abstract: Through the self?built test platform, the fire suppression test of ternary lithium?ion battery with water extinguishing agent containing additives was carried out. Different mass fractions of surfactant, potassium salt and microcyst fire extinguishing agent were selected to carry out the fire extinguishing test of aqueous fire extinguishing agent containing a single additive, and on this basis, three composite additive formulations were compounded, and their effectiveness in fire extinguishing of lithium?ion batteries was studied experimentally. The results show that the cooling rate and flame suppression ability of the fire extinguishing agent containing composite additive are generally better than the fire extinguishing agent containing a single additive, and the CF?2 fire extinguishing agent has the best fire extinguishing effect on ternary lithium?ion battery fire. The formula of CF?2 fire extinguishing agent was tested for physical and chemical properties and antifreeze optimization, and the optimized fire extinguishing agent formula was CF?4:SDS(1.5%),urea(0.34%),triethanolamine(0.024%),K2C2O4(1.2%),N,N?dimethylformamide(0.6%),ethylene glycol(0.3%),polyacrylamide(0.1%). Tests have shown that the formulation is not only suitable for lithium battery fire, but can be engineered under certain conditions.

Key words: lithium-ion battery, thermal runaway fire, additive, aqueous fire extinguishing agent, recipe optimization