典型灭火气体对锂离子电池热失控作用特性研究

Research on the thermal runaway characteristics of lithium-ion batteries in the fire-extinguishing gas

为研究典型灭火气体对锂离子电池热失控的作用特征,以4 040 mAh软包锂离子电池为研究对象,采用热安全测试装置(EV+ARC)开展空气、氮气、七氟丙烷等作用下的电池热失控绝热温升实验。结果表明:七氟丙烷、氮气气氛下,电池绝热温升条件下起始放热温度升高;120～150℃七氟丙烷保护气氛的放热速率最低,其次是氮气;七氟丙烷、氮气和空气气氛下最高绝热温升依次为199.96、222.77、271.65℃;一旦突破不可逆临界温度145～150℃,电池内短路大面积发生,进入快速爆燃阶段;灭火气体对初始自放热诱导阶段的抑制较明显,对快速爆燃热失控阶段的影响较弱。

To study the characteristics of typical extinguishing gas effects on thermal runaway of lithium-ion batteries,4 040 mAh softpackaged lithium-ion batteries were chosen as the representative samples.Thermal-safety test equipment(EV+ARC)was used to test the thermal runaway adiabatic temperature rise of batteries under the action of different fire extinguishing gases such as air,nitrogen,and heptafluoropropane.The experimental results showed that with the protection of heptafluoropropane and nitrogen atmosphere,the initial exothermic temperature of the battery increases under the condition of adiabatic temperature rise;the heat release rate of the battery with the protection of heptafluoropropane at 120~150℃is the lowest,followed by nitrogen;in the heptafluoropropane,nitrogen,and air atmospheres,the highest adiabatic temperature rises are 199.96,222.77,and 271.65℃,respectively;once the irreversible critical temperature 145~150℃is exceeded,a large area of battery internal short-circuit occurs and enters the rapid deflagration phase;the fire-extinguishing gas has obvious inhibition to the initial self-heat release induction phase,and has weaker influence on the rapid deflagration heat runaway phase.