锂离子电池组热失控蔓延热传递机制的影响研究

分析通风和电池组数量对电池组热失控发展蔓延热传递机制的影响.选择荷电状态(SOC)为100％的镍钴锰(NCM523)三元锂离子动力电池组作为研究对象,改变电池组底部外加热源的热流量和加热时间,利用多物理场仿真软件COMSOL,进行热滥用导致不同风速通风环境和不同电池数量电池组热失控过程的模拟.结果表明:随着风速不断增大...

Study on the Effect of the Thermal Transfer Mechanisms in the Thermal Runaway Process of Lithium-ion Battery Packs

The influence of ventilation and the number of battery packs on the thermal runaway development and spread heat transfer mechanism of battery packs was analyzed.The nickel-cobalt-manganese(NCM523)ternary lithium-ion battery pack with 100%charge(SOC)was selected as the research object,the heat flow and heating time of the external heat source at the bottom of the battery pack were changed,and the COMSOL multiphysics was used to simulate the thermal abuse of battery packs in different wind speed ventilation environments and different battery numbers.The results showed that,with the continuous increase of wind speed,the convective heat transfer loss between the battery pack and the surrounding environment increases,and the thermal runaway spread process of the battery pack is effectively inhibited.Affected by the heat conduction mode,the number and arrangement of battery packs are different,and the route of thermal runaway spread of battery packs is different.The closer the battery to the external heat source,the earlier the thermal runaway is triggered,and the higher the starting temperature for triggering thermal runaway.The more batteries the battery pack contains,the greater the heat flow required to trigger thermal runaway of the battery pack,however,after the thermal runaway of the first battery,the time interval for subsequent batteries to trigger thermal runaway is sharply shortened,and the severity of the consequences of thermal runaway of the battery pack increases.