Abstract The increasing use of lithium-ion batteries, coupled with the increasing prevalence of electric vehicles, also increases the demand for battery thermal management systems. If the significant amount of heat generated by these batteries during operation cannot be adequately dissipated, the battery temperature rises, its performance decreases, and it can lead to failure. In this study, the effects of the use of an Al 2 O 3 -ZnO-water hybrid nanofluid on a cold plate for Li-ion electric vehicle batteries under various operating parameters on heat transfer rate, heat transfer coefficient, battery surface temperature and temperature difference, pressure drop, and voltage change were experimentally investigated. Experiments were conducted using three different volume flow rates (6 LPM, 7 LPM, 8 LPM), three different coolant inlet temperatures (10 °C, 15 °C, 20 °C), five different discharge rates (1 C, 2 C, 3 C, 4 C, 5 C), and four different nanoparticle volume concentrations (0.00625%, 0.0125%, 0.025%, 0.05%), and the findings were compared with pure water. As a result, the newly developed hybrid nanofluid was found to enhance the heat transfer rate by 42.5%, the heat transfer coefficient by 42.1%, and the pressure drop by 25.8%, while reducing the battery temperature and temperature difference by 3.8 °C and 32.8%, respectively, compared to pure water. In addition, the maximum PEC value of 1.15 indicates that the hybrid nanofluid is advantageous in terms of thermo-hydraulic performance. It was concluded that increasing volume concentration of the nanofluid and flow rate positively affects cooling performance and that battery cooling by natural convection is insufficient for discharge rates higher than 1 C. This research highlights the potential of Al 2 O 3 -ZnO-water hybrid nanofluid as an effective coolant to improve battery performance in electric vehicle applications.
Bilgili et al. (Thu,) studied this question.