Experimental investigation of thermal performances of batteries with different fin structures and phase change materials

Battery is used in many areas in our daily life. It is especially preferred in portable devices, medical devices in the defense industry, and recently in vehicles. Although it is possible to choose batteries according to factors such as power density, lifespan and cost, thermal management must be done for each battery type. Thanks to thermal management, battery life, thermal degradation, explosion and burning risks can be prevented. In this thesis study, the thermal performances of batteries under different operating conditions will be examined experimentally. First, the thermal performance of the battery group and the single battery will be determined without any application and the temperature profiles of the batteries will be revealed. At this stage, it will be determined which parts of the battery heat up more and thermal application will be determined as a solution to this problem. After the temperature profile of the battery is determined, experimental chambers will be created using a certain thickness of phase change material in the first layer and different types of fins in the second layer. When charging and discharging batteries at different currents, first the thermal performance of the batteries will be determined in cases where there is no air flow. Then, the thermal performance of the batteries will be determined by conducting experiments at certain air speeds in the air duct. In this thesis study, the surface temperature of the batteries, the phase change material temperature, the temperatures of the entering and leaving air, the ambient temperature, and the pressure drop in the experiment room will be measured. The results obtained will be interpreted for each experiment chamber with different fins and by comparing them with the cases where there is no fin and phase change material, and the results will be examined. In addition, the experimental results obtained from the thesis study will be compared with similar studies in the literature, and the effect of phase changing materials and fins applied to the experimental room on thermal management will be revealed. Additionally, Nusselt correlations will be obtained in experiments involving air flow and will be presented to the literature. Finally, the thermal efficiency calculation will be made using the heat transfer and pressure drop of the battery groups in the insulated state and the heat transfer pressure drop in the experiments where the phase changing material and finned geometries are created and the performance of this applied thermal method will be determined.