Study on thermal runaway warning method of lithium-ion battery

Abstract

The battery pack design is limited by manufacturing cost and space energy, so it is impossible to set a temperature sensor on each battery and accurately determine the whole battery pack's temperature distribution by BMS (Battery Management System). However, the temperature is an important parameter to judge the security features of the battery. The finite element model could be dedimensionalized by a lumped parameter heat transfer model to meet the computational capacity of BMS, and the real-time temperature distribution within the battery module could be calculated and the thermal runaway location could be predicted. A temperature distribution back-calculated model for the battery module based on three measurement points was established. The calculation result showed that if only the temperature term was input, the temperature of the node interval without the heat source term was remarkably accurate. However, the temperature distribution results in the node interval with the heat source term meeting a vast error. After taking the temperature change rate into account, the difference between the calculated result and the actual temperature distribution is slight. It realizes an accurate calculation of the temperature distribution.