Currently, effective suppression methods are still required to deal with lithium-ion battery (LIB) fires. In this paper, a novel synergistic fire extinguishing method of gas extinguishing agent (C₆F₁₂O, CO₂ and HFC-227ea) and water mist is designed to evaluate the effect of their combination. A 243 Ah large-scale LIB with LiFePO₄ as cathode is used in this work. Several cell parameters are measured to evaluate the suppression effect of fire extinguishing method, such as extinguishing time, maximum temperature, mass loss and heat release rate. Meanwhile, the cooling effect, fire extinguishing effect and economic benefit of different fire extinguishing methods are all considered. Results show that the suppression effect of synergistic fire extinguishing method is better than that of the single agent. Single application of water mist can hardly extinguish the flame, while the combination of gas extinguishing agents and water mist can extinguish the flame finally. However, the C₆F₁₂O extinguishes the flame immediately, while CO₂ has a longer extinguishing time, and HFC-227ea cannot extinguish the flame. So in these experiments, the C₆F₁₂O combined with water mist exhibits the best extinguishing and cooling effect. The CO₂ combined with water mist has good economic benefit, better fire extinguishing effect and cooling effect in these experiments, which can also be considered in suppressing LiFePO₄ LIB fires.

当前，仍需要有效的抑制方法来应对锂离子电池（LIB）火灾。本文设计了一种新型的气体灭火剂（C ₆ F ₁₂ O，CO ₂和HFC-227ea）与水雾的协同灭火方法，以评估它们的组合效果。带有LiFePO _4的243 Ah大型LIB作为阴极用于这项工作。测量了几个电池参数以评估灭火方法的抑制效果，例如灭火时间，最高温度，质量损失和放热率。同时，考虑了不同灭火方法的冷却效果，灭火效果和经济效益。结果表明，协同灭火方法的抑制效果优于单一药剂。一次喷洒水雾几乎不能扑灭火焰，而气体灭火剂和水雾的结合最终可以扑灭火焰。但是，C ₆ F ₁₂ O立即熄灭火焰，而CO ₂灭火时间更长，并且HFC-227ea无法灭火。因此，在这些实验中，C ₆ F ₁₂ O结合水雾表现出最佳的灭火和冷却效果。在这些实验中，CO ₂结合水雾具有良好的经济效益，较好的灭火效果和冷却效果，这在抑制LiFePO ₄ LIB着火方面也可以考虑。