Numerical Study on Thermal Runaway of LFP batteries Triggered by Low Temperature Heating

Abstract

With the wide application of electric vehicles (EVs) in cold areas, low temperature heating of battery is becoming more and more mature, and the way of battery bottom heating is also widely used in EVs. Nevertheless, the battery is not completely safe during the heating process, and there may be a risk that the heating plate trigger the battery to overheat. Firstly, a thermal runaway (TR) model of the battery is built, and the simulation results are compared with the experimental results to verify the accuracy. Subsequently, a bottom heating module is added to the TR model to simulate and analyze. Results show, when the heat flux exceeds 1500 J (m² s)⁻¹ and heating continuously for over 26,787 s, TR is triggered. As the heat flux increases, the TR is triggered nearly half the time earlier, and the maximum temperature reached also increases by 7.62°C. Additionally, the ambient temperature has a great effect on the time of continuous heating to TR at low temperature, and has little effect on the maximum temperature. This work provides a reference for the model study of TR in the case of low temperature heating.