水凝胶对磷酸铁锂电池灭火实验性能

Study on fire-extinguishing performance of hydrogel on lithium-iron-phosphate batteries

水系灭火剂因兼具比热容高和隔绝性强的特点,在对锂电池火灾的扑灭过程中相对于其他灭火剂更为高效,然而传统水系灭火剂的保水以及附着能力有待进一步提高。本工作报道一种使用羧甲基纤维素(carboxymethyl cellulose)与氯化铝(AlCl_(3))溶液混合制备的水凝胶络合物灭火剂。温度敏感性研究表明:凝胶分子的亲水性使其表现出保水性强和附着力高的特点,且在低温时有较好的流动性,高温又表现出足够的黏性,在方便使用的同时,又增加了锂电池全面降温效果。为探究水凝胶灭火剂的灭火性能,对磷酸铁锂电池组(LIBs)展开燃烧实验,通过对水凝胶灭火剂使用与否两种情况下的火焰图像、电池高度、燃烧温度等燃烧特性参数进行分析,对水凝胶灭火剂的灭火效果做出评估。结果表明:在喷射灭火剂后,电池组温度迅速降低至热失控温度200℃以下;水凝胶灭火剂对射流火焰有一定限制作用,且可以阻碍多个电池间热量传递;在使用水凝胶灭火剂后,电池均未发生复燃,说明水凝胶对锂电池火灾具有较好的灭火效果。

Water-based fire-extinguishing agents are used to extinguish lithium-battery fires with high specific-heat capacity and strong isolation.However,the water retention and adhesion capacity of traditional water extinguishing agents need to be improved.A hydrogel complex fire-extinguishing agent prepared by mixing Carboxymethyl Cellulose with AlCl_(3) can solve this problem.Temperature-sensitivity studies show that the gel molecules exhibit strong water retention and adhesion,giving the agent good fluidity at low temperatures and enough viscosity at high temperatures.This phenomenon increases the overall cooling effect of lithium batteries.To explore the fire-extinguishing effect of hydrogel agents,we conducted a combustion experiment on lithium-ion battery(LIB)packs.In this study,the fire-extinguishing effect of the hydrogel agent was evaluated by analyzing the flame image,flame height,and battery temperature in cases where the hydrogel agent was used and when it was not used.The results show that the temperature of the battery packs reduced below 200℃after spraying.The hydrogel agent has a certain restrictive effect on the jet flame and can hinder the heat transfer between multiple batteries;after the use of the hydrogel agent,the batteries did not reignite,indicating that the hydrogel has a good fire-extinguishing effect on LIB fire.