气压及加热功率对锂离子电池热安全的影响机制  

Influence mechanism of air pressure and heating power on thermal safety of lithium-ion battery

作　　者：何俊贤 谢松 陈现涛 HE Junxian;XIE Song;CHEN Xiantao(College of Civil Aviation Safety Engineering,Civil Aviation Flight University of China,Guanghan 618307,China)

机构地区：[1]中国民用航空飞行学院民航安全工程学院,广汉618307

出　　处：《北京航空航天大学学报》2023年第11期3197-3206,共10页Journal of Beijing University of Aeronautics and Astronautics

基　　金：四川省科技计划(2022YFG0236);民机火灾科学与安全工程四川省重点实验室项目(MZ2022JB02)。

摘　　要：随着锂离子电池的普及应用,其在航空低气压环境下的热安全问题受到广泛关注。对此,在20~95 kPa的气压环境下,以30~100 W的加热功率诱导电池热失控,通过电池热失控现象、温度及时间的分析,研究航空低气压环境下加热功率对锂离子电池热安全行为的影响机制。研究表明:气压的降低导致电池安全阀打开时间提前,但由于低气压环境下对流换热系数和特征达姆科勒数的减小,电池从安全阀开启到热失控的过渡时间延长;而加热功率的提高显著缩短了电池的热失控时间,加剧了电池热失控燃爆,同时也缩短了电池的加热时间,导致外部热源传递给电池的热量减少,热失控过程中电池表面峰值温度降低;在二者的综合作用下,电池的热失控时间总体呈现出随功率增加而减小的趋势,但气压的作用导致其变化规律呈现出明显差异。为实现气压及加热功率综合影响下电池热失控时间的预测,通过多项式拟合,构建电池热失控时间预测模型,预测精度控制在(3±2) s。With the popularization and application of lithium-ion batteries,the thermal safety problem in aviation low-pressure environments have has attracted wide attention.The lithium-ion batteries were induced to thermal runaway under the heating power of 30-100 W at 20-95 kPa.Through the analysis of the thermal runaway phenomenon,temperature and time,the influence mechanism of the heating power on the thermal safety behavior of lithium-ion batteries in aviation low-pressure environments was discussed.The results showed that the reduction of air pressure caused the opening time of the battery safety valve to advance.However,due to the reduction of the convection heat transfer coefficient and characteristic Damkoler number under low-pressure environments,the transition time from the opening of the safety valve to the thermal runaway of the battery was prolonged.The battery’s thermal runaway period was greatly reduced by the increase in heating power,which also made the battery's thermal runaway explosion worse.The heating time was shortened,resulting in less heat transferred to the batteries from the external heat source,and the peak temperature of the battery surface was reduced.Under the combined action of the heating power and air pressure,the thermal runaway time of the battery generally showed a trend of decreasing with the increase of power.However,due to the effect of air pressure,its change law showed and obvious difference.A prediction model of battery thermal runaway time has been built by polynomial fitting,and the forecast accuracy has been regulated within(3±2)s.This was done in order to achieve the prediction of battery thermal runaway time under the combined impact of air pressure and heating power.

关 键 词：低气压 加热功率 锂离子电池 热失控 热安全 

分 类 号：TM912[电气工程—电力电子与电力传动]