Cooling performance investigating of battery thermal management system using water-based nanofluids

For several years, air pollution from internal combustion engines has become a significant issue in the transportation sector. Hence, electric vehicles (EVs) have been developed to reduce emissions. Lithium-ion battery is the most important component in EVs which is used for energy storage. Generally, the battery generates some amount of heat during charging and discharging which results in a rising in the battery temperature. It has a direct impact on the battery’s performance and its life span. When the battery temperature rises excessively beyond an appropriate temperature, it may explode. To keep the battery temperature within a recommended range of 25 – 40°C with the different temperatures between cells less than 5°C, therefore the use of battery thermal management system (BTMS) is necessary. There are several types of battery cooling systems such as liquid cooling, air cooling, and phase-change material (PCM) cooling. Therefore, the goal of this study is to numerically investigate the improvement of cooling performance when water-based nanofluids is used as a working fluid in the liquid-cooled BTMS by using ANSYS Fluent program. The accuracy of the simulation model was validated with the experimental results via the term of battery surface temperature. The result showed that the maximum deviation between the simulation and the experiment was reported at 1.83 percent, which could be acceptable. Furthermore, three different geometries of cooling flow channels (model A, model B, and model C) were designed to investigate the capability of heat rejection from the batteries. It was noticed that the cooling system of model C using pure water as a coolant had the highest heat rejection per unit mass of coolant. Then, adding nanoparticles into pure water was implemented in model C. The study discovered that using water/SiC (98:2) as a working fluid reduced the maximum temperature of the battery by up to 2.285 °C at the inlet velocity of 0.033 m/s. Nonetheless, the battery temperature was still beyond the recommended range. Therefore, to control the maximum temperature in a safe range, the inlet velocity of fluid flow was increased to be 0.066 m/s in order to enhance the heat transfer. The result showed that using water/SiC (99:1) could control the maximum temperature at 28°C with a temperature difference of 4.8°C which was acceptable.