A novel hybrid cooling system for a Lithium-ion battery pack based on forced air and fins integrated with phase change material
Mohanad F. Hassan, Abdul Hadi N. Khalifa, Ahmed J. Hamad
Abstract
• The thermal management system for Li-ion batteries used in electric vehicles is essential in controlling the battery temperature at a safe certain temperature. • Using phase change material (PCM) for the Li-ion battery cooling system is an effective tool because of its high latent heat and the merit of not requiring extra power. • Equipping a Li-ion battery cooling system with fins will improve the heat exchange and dissipate the generated heat to prevent battery thermal runaway and heat propagation. Therefore, the system can also adapt to diverse climatic conditions. • PCM-Air cooling model offers improved thermal performance, battery pack temperature stability, and thermal damage protection. It demonstrates superior cooling performance to the air cooling model under various C-discharge rates and air velocities. • Improving the thermal performance of battery cooling systems will extend the utilization of Li-ion battery cells. This can reduce carbon emissions by utilizing renewable energy sources and addressing sustainability issues to mitigate climate change. Lithium-ion batteries are increasingly important due to their high energy density and long lifespan, especially in electric vehicles and other applications as a power source. However, they face challenges, including thermal runaway and safety risks from thermal damage to an explosion. Therefore, effective cooling methods and strong thermal management systems ensure their safety and optimal performance. This study experimentally investigates two air cooling models for a lithium-ion battery pack to evaluate its thermal performance for different air velocities and three discharge rates of the battery: 1C, 2C, and 3C. The first model (Air model) is a forced air cooled battery pack of 9 cells tested under different air velocities: 1, 2, and 3 m/s. The second cooling model (PCM-Air model) is a hybrid that uses forced air with extended copper fins enclosed in the phase change material (PCM) shell. Compared to the Air model, the temperature maximum (Tmax) and the temperature difference (ΔTmax) for the PCM-Air model are significantly reduced. At air velocity v = 0 m/s, Tmax for the PCM-Air model was 43.5, 50.2, and 58.2 ℃ for 1C, 2C, and 3C rates respectively, with ΔTmax reductions of 62 %, 48 %, and 41 %, respectively. At relatively higher velocity v = 3 m/s, Tmax dropped to 40, 47.6, and 55 ℃, with similar reductions in ΔTmax by about 61, 46.5 and 39 % for 1C, 2C, and 3C discharge rates respectively. The PCM-Air model findings showed better cooling performance and thermal management for Li-ion batteries than the Air cooling model.