Thermal performance improvement of an air-cooled 18650 NMC battery module: A novel busbar design that acts as a turbulator

Today, Lithium-ion batteries are preferred as popular energy storage tools in many fields such as electronic devices, especially electric vehicles. During the discharge of modules and packs formed by combining many battery cells, undesirable temperature increases are experienced due to excessive heat generation. Thus, thermal management of the battery packs is crucial. In this work, thermal and hydraulic performance analysis of the two air-cooled 18650 NMC battery modules, one with a novel designed twisted busbar and the other with a conventional busbar, are performed numerically. Temperature and pressure drop predictions are achieved at different values of air inlet velocity, discharge rate, depth of discharge, and twist diameter of busbar using CFD method. Besides, the Multi-Scale Multi-Domain battery model is validated experimentally. According to the numerical results, the novel designed twisted busbar provides 1.84 %, 2.93 %, and 3.81 % reduction in maximum battery module temperature for 5 m/s air inlet velocity under discharge rates of 2C, 3C and 4C, respectively. The average battery module temperature drops by 6.6 °C thanks to the use of a twisted busbar. Using a twisted busbar results in a maximum pressure drop increase of 119 Pa compared to the conventional busbar. As the twist diameter of the busbar increases, the battery temperature decreases significantly, and the pressure drop increases, especially at high air velocity conditions. In addition, when the twist diameter increases from 5 mm to 15 mm, the weight/volume ratio increases by approximately 0.9 %. © 2024 Elsevier Ltd