Effect of passive thermal management system on the electro-thermal performance of battery module

Passive thermal management systems (BTMS) based on phase change material (PCM) have been proposed in many articles, but more attention has been paid to the temperature effect of BTMS, and the influence of BTMS on the electro-thermal performance of battery module has rarely been studied. Therefore, composite PCM composed of lauric acid, expand graphite (EG) and graphene (GR) with a mass ratio of 8:1.5:0.5 is prepared and used for temperature control of Li-ion battery. Then, a series of experiments are performed to research the performance of the thermal management module based on the cPCM, including thermal property analysis, discharge tests under standard and extreme conditions. In addition, the Gaussian process regression (GPR) model is trained and tested with internal resistance data measured over a wide temperature range, and then combined with an electro-thermal model to estimate the heat generation of batteries and further research the effect of the BTMS on discharge performance. The experimental results show that the maximum temperature (Tmax) of the batteries with cPCM is 47.41 °C, and the maximum temperature difference (ΔTmax) between the batteries is 1.46 °C in the 2C discharge process at 40 °C. The estimation results show that the heat generation of batteries with cPCM is higher than that of the batteries without cPCM under the same working conditions, and it is more sensitive to ambient temperature even without phase transition.