Experimental investigation of liquid-cooled battery thermal management system

Many research and development studies are carried out on battery systems that directly affect vehicle performance in the electric and hybrid electric vehicle sectors. In this regard, it has focused on the temperature problem, which occurs at the time of charge/ discharge and seriously damages battery cells when it cannot be controlled in the battery pack. In order to overcome this mentioned problem, battery thermal management systems have vital importance. In this study, experimental research was carried out on the cooling performance of the liquid-cooled battery thermal management system by placing the battery pack consisting of 18 cylindrical lithium-ion batteries in an S-type liquid cooling channel made of copper plates with a wall thickness of 1.5 mm. In the charge and discharge experiments of the battery pack, the cooling performances of 15 °C, 25 °C and 35 °C liquid inlet initial temperatures at 475 ml/min, 625 ml/min and 790 ml/min liquid flow rates were investigated. Although a clear conclusion about the effect of liquid inlet temperature cannot be obtained due to the fact that an adiabatic experimental environment was not provided, it has been deduced that inlet temperatures between 15 °C and 25 °C can contribute to battery pack homogeneity and decrease the maximum temperature. In terms of cooling performance, the combination of 15 °C starting liquid inlet temperature and 790 ml/min liquid flow rate has founded to be the most effective result. In these conditions, the average temperature of the battery pack, the maximum temperature, and the maximum temperature difference values are reduced by approximately 39.35%, 39.75%, and 62.10% respectively. Power consumption and cooling performance when evaluated together, it is seen that the most efficient combination is 15 °C initial liquid inlet temperature and 625 ml/min liquid flow rate.