Investigation of the effects of different nanoparticle reinforced liquids on the cooling performance of the battery thermal management system

Electric vehicles are gaining importance in the transportation sector as an environmentally friendly option to replace fossil fuels and reduce carbon footprint. Battery packs, which are the power source of electric vehicles, are high-cost and thermally sensitive components. The temperature rising and temperature distribution of battery packs during charging and discharging processes affect their performance, life, and safety. Therefore, an effective cooling system is required to keep the operating temperature of the battery packs in the optimum range and to ensure homogeneous temperature distribution. In this study, a battery module containing 18 cylindrical lithium-ion batteries was placed in a labyrinth-type cooling channel. The cooling channel is made of copper. Pure water, boron nitride (BN)-water nanofluid, and titanium dioxide (TiO2)-water nanofluid were passed through the cooling channel and the thermal performances of the cooling fluids were compared. Concentrations of 0.1% by mass of BN-water nanofluid and 0.1% by mass of TiO2-water nanofluid were used. Experiments were carried out at 1C charge and 1C, 2C, and 3C discharge rates to test the battery pack under different operating conditions. In all experiments, the inlet flow rate of the refrigerants was kept constant at 790 ml/ min and the inlet temperature at 25 oC. According to the experimental results, it was seen that BN-water nanofluid provides better cooling performance compared to other fluids and makes the temperature distribution of the battery module more homogeneous. This study aims to contribute to the development of battery thermal management systems in electric vehicles.