Features and Spread Mechanism of Thermal Runaway for Electric Car Batteries

Abstract

Thermal runaway of the battery pack is a main safety accident of lithium-ion batteries. To improve the safety of lithium-ion batteries, it is of great significance to explore the features and development mechanism of thermal runaway. However, the previous studies mainly focus on a single triggering condition of thermal runaway, and fail to achieve a high modeling accuracy. Hence, this paper probes deep into the features and spread mechanism of thermal runaway for electric car batteries. Firstly, the thermo-physical (TP) parameters were acquired from the batteries, and several key parameters were identified, including the heat transfer parameters in the chamber of accelerating rate calorimeter (ARC), and the thermal parameters of battery debris. Next, the thermal runaway features of the batteries were discussed in stages, and the internal heat yield of batteries was calculated for each stage. After that, the thermal runaway spread was modeled, and a discussion was held on the influence of post-thermal runaway TP parameter changes over the spread features of thermal runaway. The proposed model was proved effective and accurate through experiments.

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