Research and evaluation of the impact of air: Cooling models on the operating temperature of lithium-ion batteries

Abstract

In this study, a Panasonic 18650 lithium-ion battery module consisting of 24 cells with multiple vents was studied and the design was optimized through numerical simulation. Compared to previous studies showing that the cooling model layout using 1 inlet and 1 outlet was improved, the cooling model with multiple vents improved the temperature difference and the maximum temperature in the cells. Specifically, the effects of multiple directions and the number of inlet/outlet cooling air were analyzed in the study, and finally the appropriate inlet velocity was discovered to be applied on the proposed model. The results showed that the arrangement of 2 inlets air holes at the center of the two ends of the battery module and 1 outlet hole at the center of the bottom surface produced the best cooling effect compared to the first model and other models. The maximum temperature (Tmax) and maximum temperature difference (ΔTmax) were reduced by 312.62 K (14 %) and 6.74 K (88 %), respectively compared to the first model. Furthermore, with the 2 inlets - 1 outlet model being the optimal cooling model for the selected model, consideration of the velocity input value to bring the model to operate in the appropriate temperature range was then carried out. The results showed that with the battery cell operating at a discharge current of 3 C, a velocity greater than 2 m/s was sufficient for the battery module to operate at the maximum temperature (Tmax) and maximum temperature difference (ΔTmax) of 306.69 K and 4.84 K, respectively without consuming much fan power.