Comparative studies on the combustion characteristics of electrolytes and carbonate mixed solvents with flame retardant additives under low pressures

Adding flame retardant additives is an effective approach to improve the safety of lithium-ion battery electrolytes. This study discusses the inhibiting effects of three flame retardant additives on the combustion characteristics of electrolyte and carbonate mixed solvent under low pressure. The experimental results show that the inhibition of flame retardant additives mainly occurs in the low-boiling carbonate control stage. In contrast, the combustion of the high-boiling carbonate control stage is promoted, and the promotion effect is more significant under low pressure. When the pressure is 40 kPa, it is difficult to maintain the combustion of the high-boiling point carbonate control stage of carbonate mixed solvent, but the carbonate mixed solvent containing phenoxycyclophosphazene. Phenoxycyclophosphazene has a better flame retardant effect on the mass loss rate and combustion time of carbonate mixed solvent compared with other additives. Due to the flame retardant effect of lithium salt, the electrolyte can only complete the combustion of the low-boiling point carbonate control stage, and the flame retardant effects of the flame retardant additives in the electrolyte on the combustion mass, mass loss rate, and combustion time are weakened as the pressure decreases. Tris (2-chloropropyl)phosphate assists in reducing the temperature of the electrolyte and carbonate mixed solution.