摘要
对于锂离子电池模组火灾,灭火剂能否抑制热失控传播非常重要.搭建了适用于多种灭火介质的测试平台,比较了不同灭火剂的冷却能力及抑制热失控传播能力.结果表明,对于三元锂离子电池,热失控后伴随的高温是热失控难以抑制的关键.当电池模组内一个电池发生热失控后,热失控将在短时间内蔓延整个模组,热失控传播非常迅速.因此,灭火剂的冷却能力至关重要.水喷淋、全氟己酮和七氟丙烷都可以快速扑灭明火.其中,降温效果从优到劣依次为水喷淋、全氟己酮和七氟丙烷.水喷淋可以有效阻止电池模组内的热失控传播,而全氟己酮和七氟丙烷仅能延缓热失控传播,全氟己酮的抑制效果优于七氟丙烷.研究结果可为电池模组的灭火设计提供试验支撑.
Abstract
The effectiveness of fire extinguishing agents in halting the propagation of Thermal Runaway(TR)in Lithium-Ion Batteries(LIB)is critical for extinguishing battery module fires.This paper outlines the construction of a fire extinguishing test platform designed for assessing a range of fire extinguishing agents.Through this platform,we compare the fire extinguishing capacity,cooling effectiveness,and ability to suppress thermal runaway propagation among different fire extinguishing agents.The findings indicate that the elevated temperatures following thermal runaway in Lithium-Ion Batteries(LIBs)with LiNixCoyMn1-x-yO2(NCM)cathodes pose a significant challenge to effective suppression.Without adequate intervention,thermal runaway in a single battery within the module swiftly escalates to engulf the entire assembly.Thermal runaway propagates rapidly within the battery module.Therefore,the cooling capabilities of fire extinguishing agents are paramount.Among the tested agents,water spray,HFC-227ea,and C6 H12O demonstrate rapid flame suppression.Notably,water spray exhibits the highest cooling efficiency compared to other agents,with C6F12O and HFC-227ea following closely behind.The primary extinguishing mechanism of water spray revolves around cooling,effectively dissipating the substantial heat generated during thermal runaway and effectively halting its propagation within the battery module.While compounds like C6F12O and HFC-227ea primarily suppress fires chemically,their cooling efficacy is limited.Although they can momentarily extinguish fires,they have minimal heat-absorbing capacity.Consequently,if the extinguishing concentration isn't sustained,there's a risk of battery reignition,particularly in elevated temperatures.Hence,compounds like C6 F12O and HFC-227ea serve to postpone rather than entirely halt the propagation of thermal runaway within battery modules.Notably,C6F12O demonstrates superior inhibitory properties compared to HFC-227ea,which struggles to effectively suppress thermal runaway.While C6F12O doesn't entirely prevent thermal runaway,it does contribute to lowering battery temperatures,reducing the rate of heat transfer,and extending the propagation timeframe.These findings offer valuable experimental insights for the design of fire suppression systems in battery modules.
基金项目
国家电网有限公司总部管理科技项目(5500-202220118A-1-1-ZN)
NETL
NSTL
万方数据