Characteristics of Thermal Runaway Propagation of Lithium Ion Battery Module Induced by Thermal Abuses in Enclosure Space

Abstract

Fire and explosion risks of electric vehicles caused by thermal runaway (TR) of battery have become the main obstacle that delaying the popularization of electric vehicles. Usually, the whole battery pack is completely burned down and destroyed, firstly caused by TR of a single battery, and then by the propagation over the whole battery pack with an extremely rapid rate. In this work, thermal runaway propagation characteristics of lithium ion battery module induced by thermal abuses in enclosure space were experimentally investigated. The results indicated that a temperature rise of 72 °C on the nearby battery was found when overheating one cell in the module with an initial temperature of 25 °C; however, no TR occurred. While for the case of overheating the whole battery module, cells were found to TR in 85 s and thus giving rise to a high temperature of 956 °C, as soon as TR firstly happened in the battery module. Violent explosion and high heat releasing rate were observed and eventually caused the damage of battery module. Therefore, the methods of mitigation of TR propagation when TR occurred in modules will become the focus of future research on the safety of lithium ion battery.