Akademik Veri Yönetim Sistemi
Journal of Thermal Analysis and Calorimetry, cilt.150, sa.19, ss.15343-15357, 2025 (SCI-Expanded, Scopus)
Lithium-ion batteries release high levels of heat energy due to the reactions inside the battery and the internal resistance of the battery while charging or discharging during use. This heat production causes the battery temperature to increase, and the increased temperature causes the battery efficiency to decrease. If the battery can be modeled thermally in a realistic manner, the maximum temperatures and maximum temperature differences generated in the battery under different loads and ambient temperatures can be obtained without actually running the battery. There are many different methods available for battery thermal modeling, and in this study, two different thermal models that have not been compared for a battery module in the literature to date were compared: the Newman, Tiedemann, Gu, and Kim (NTGK) model, which is one of the ready-made modules in the ANSYS Fluent program, and the Volumetric Heat Source (VHS) model obtained by writing a user-defined function (UDF) in the ANSYS Fluent program. The experimental data obtained were compared with both the VHS model and the NTGK model, and the suitability of the thermal models used was examined. As a result, it has been observed that if the change of battery internal resistance and battery entropy coefficient is determined correctly, the results obtained with the VHS model are closer to the experimental results than the results obtained with the NTGK model. It has also been found that, at high discharge rates, joule heat is more significant than entropic heat, increasing with the square of the discharge current. At low discharge rates, entropic heat plays a larger role and can be negative at certain battery states of charge, reducing temperature increases.