电解液阻燃添加剂对锂离子电池针刺安全性影响试验研究

Experimental study on the effect of electrolyte flame retardant additives on the nail penetration safety of lithium-ion battery

分别采用正极为三元材料的电池和正极为三元磷酸铁锂混合材料的电池考察针刺过程中的电池电压和温度的变化,研究发现三元电池的安全阀喷口温度744.8℃,三元磷酸铁锂混合材料电池的安全阀喷口温度380.3℃;考察了加入电解液阻燃添加剂后电池针刺过程中的电压和温度变化,加入阻燃添加剂后,三元电池安全阀喷口温度为618.7℃,与未加阻燃添加剂的电池相比,温度下降了126.1℃;三元磷酸铁锂混合材料电池安全阀喷口温度277.6℃,与未加阻燃添加剂的电池相比,温度下降了102.7℃。表明阻燃添加剂有显著的抑制电池内部热失控的作用,对于电池针刺安全性有明显的改善。

The changes of battery voltage and temperature during nail penetration test are investigated by using the battery with NCM material and with NCM and LFP mixed material as the positive electrode.It is found that the vent temperature of NCM battery was 744.8℃,and the vent temperature of NCM and LFP mixed material battery was 380.3℃.The changes of voltage and temperature of battery with electrolyte flame retardant additives.during nail penetration test are studied after adding flame retardant additives,the vent temperature of NCM battery is 618.7℃,which dropped by 126.1℃comparing with batteries without flame retardant additives;the vent temperature of NCM and LFP mixed material battery is 277.6℃,which dropped by 102.7℃comparing with batteries without flame retardant additives,indicating that the flame retardant additive can significantly inhibit the thermal runaway of the battery and significantly improve the safety of battery during nail penetration.