Numerical studies for thermal management of lithium-ion batteries

In the thesis study, three different battery thermal management systems (BTMS) were designed, including Phase-changing material (PCM), liquid-assisted and hybrid, in order for li-ion batteries to operate at the ideal operating temperature. The maximum temperature and temperature distribution have been analyzed to determine the effectiveness of BTMS. For the 20 Ah capacity battery module, simulations were carried out at various discharge rates (2C, 3C, and 4C) in the absence of cooling. An appropriate thermal management solution was then determined by doing simulations of FDM, liquid-assisted, and hybrid BTMS. The effectiveness of PCM and BTMS was studied at three different discharge rates. For liquid-supported BTMS, the thermal performance of water and Al2O3 nanofluid coolin medium was investigated at four different Reynolds numbers (Re) (250, 500, 750, and 1000), three different volume ratios (0.5%, 1%, and 2%) and four different nanoparticle geometries (Oblate spheroid, block, cylinder, and platelet). The cooling efficiency of hybrid BTYS was researched using four different Re values and three different volume ratios, as well as the effect of cooling channels on thermal performance on PCM. Ansys Fluent program, which is a computational fluids software, was used for all simulations performed in this study. When the findings were evaluated, it was discovered that Hybrid BTMS produced a 28% improvement in maximum temperature, while PCM and liquid-assisted cooling approaches provided 26% and 27% improvements, respectively. When the temperature difference was investigated, however, it was discovered that only the hybrid and phase-changing materials lowered it below 5 °C, which is the appropriate temperature difference. By reducing the liquid phase distribution in the solid phase and the melting start time using the hybrid cooling technique, paraffin can be cooled more effectively. It has been discovered that hybrid BTMS is the best cooling method for the battery module because of this.