Abstract
This study analyzed the correlation between various design parameters and cooling performance (CP) of the immersion cooling system for thermal management of lithium-ion batteries (LIBs), theoretically. The Multi-Scale Multi-Dimensional (MSMD) Newman, Tiedeman, Gu, and Kim (NTGK) empirical model was used to consider the electrochemical heating of the battery. The CP of the immersion cooling system was analyzed according to the inlet/outlet location, dielectric fluid, cell spacing, C-rate, and mass flow rate (MFR). As a result, the Z-type inlet/outlet location, Novec 649 dielectric fluid, and 2 mm cell spacing were most suitable. As the mass flow rate increased, the maximum battery temperature (Tb.max) was confirmed to remain within the appropriate operating temperature range of 45 °C or lower for battery operation. However, under discharge conditions of 4 C-rate or higher, the temperature difference between battery cells (Tb.diff) significantly exceeded the safety limit of 5 °C. Additionally, as the mass flow rate of dielectric fluid increased, Tb.max and Tb.diff decreased by 20.6 % and 50.6 %, respectively. The impact of design parameters on CP was analyzed, and based on the simulation results, a prediction equation was developed to predict Tb.max and Tb.diff, which have a high correlation of over 0.908.
