Explosion behavior investigation and safety assessment of large-format lithium-ion pouch cells  

作　　者：Tongxin Shan Zhenpo Wang Xiaoqing Zhu Hsin Wang Yangjie Zhou Yituo Wang Jinghan Zhang Zhiwei Sun 

机构地区：[1]National Engineering Research Center of Electric Vehicles,Beijing Institute of Technology,Beijing 100081,China [2]Materials Science and Technology Division,Oak Ridge National Laboratory,Oak Ridge,TN 37831,United States [3]State-assigned Electric Vehicle Power Battery Testing Center,China North Vehicle Research Institute,Beijing 100072,China

出　　处：《Journal of Energy Chemistry》2022年第9期241-257,I0007,共18页能源化学（英文版）

基　　金：sponsored by the China Postdoctoral Science Foundation(China National Postdoctoral Program for Innovative Talents,BX2021036);the National Natural Science Foundation of China(52072040,U21A20170);supported by the Department of Energy(DOE),Office of Electricity(OE)at Oak Ridge National Laboratory managed by UL-Battelle LLC(DE-AC0500OR22725)。

摘　　要：Large-format lithium-ion(Li-ion) batteries with high energy density for electric vehicles are prone to thermal runaway(or even explosion) under abusive conditions. In this study, overcharge induced explosion behaviors of large-format Li-ion pouch cells with Li[NiCoMn]Ocathode at different current rates(C-rates)(0.5C, 1C, 2C) were investigated. The explosion characteristics of the cells were elucidated by discussing the evolution of the cell voltage, the surface temperature and the shock wave pressure.Generally, the whole overcharge process could be divided into four stages according to the evolution of several key parameters and the overcharge behaviors;the overcharge C-rate has a great influence on cells’ thermal behaviors. The experimental results showed that the thermal runaway process of Liion cells caused by overcharging consisted of two kinds of explosions, physical explosion and chemical explosion. The existence of observable negative pressure zone in the pressure curves indicated that the Li-ion cells are not a self-supplying oxygen system during the explosion. Further, the explosion dynamics parameters were matched. An explosion TNT-equivalent conversion strategy that depended on the pressure of the shock wave was utilized to evaluate the released energy and its hazards. In addition, with respect to the overcharge of Li-ion pouch cells, a safety assessment method and a safety management method were proposed based on the explosion behaviors. From the perspective of battery safety, this study is of great significance for the safety design of Li-ion cells and can provide guidance for engineers to optimize the safety function of battery packs.

关 键 词：Lithium-ion battery OVERCHARGE Explosion behavior Safety Explosion dynamics 

分 类 号：TM912[电气工程—电力电子与电力传动]