Numerical Investigations on Immersion Cooling of Lithium-Ion Batteries using Different Coolants

Abstract

Due to its increased energy density, longer lifespan, long cycle life, and quick charging capabilities, lithium-ion batteries (LIBs) have become increasingly popular over the past few years in household appliances, electric vehicles, and in the energy sector, such as for energy storage at thermal power plants. Batteries can be used to store excess energy from solar panels and wind turbines for use during periods of low energy production (at night or on windless days). This increases the efficiency and stability of renewable energy sources. However, LIB is extremely sensitive to temperature, presenting difficulties with thermal management. This study involves the numerical analysis of a 4 × 4 arrangement of LIB cells with immersion cooling and is conducted using three different cooling fluids, including water, mineral oil, and Al₂O₃/water nanofluid. The modelling is carried out using SolidWorks, and thermal analysis is carried out in ANSYS Fluent. By varying the operational and geometrical parameters, their effects on thermal performance were studied. The results show that water and nanofluid work better than mineral oil. At higher discharge rates of 3C and 5C, water and nanofluid limit the average temperature rise of the battery module under 5°C. Varying the flow rates from 10 mLPM to 1.0 LPM showed that the average temperature decreased with an increase in flow rate. When changing the inlet temperature of the battery module from 298 to 308 K, it resulted in increased cell surface temperature and decreased heat transfer. The study shows that with a high flow rate and a low inlet temperature, the temperature rise is minimal even at a higher discharge rate of 5C.