Heat transfer enhancement of a lithium-ion battery cell using vertical and spiral cooling fins

Abstract

Lithium-ion batteries are widely regarded as the primary source of power for electric cars due to their high energy density, long lifespan, and lack of memory effect. However, their efficacy and safety greatly depend on the temperature at which they operate. Therefore, a battery thermal management system (BTMS) is crucial to ensure the safety of an electric vehicle. This research presents a model of a BTMS that employs a single cylindrical lithium-ion with longitudinal and spiral fins on the cell surface to investigate its cooling effectiveness. Effects of the fin’s number, rotation, thickness, length, and position are assessed at various current rates. The results show that the fins reduce the maximum cell temperature when compared to a finless case and become more effective at a low Reynolds number. Despite the fact that increasing the number of fins enhances the heat transfer area, when the number of fin reaches more than 3, they become a barrier to the flow around the cell and hence increase the battery temperature. The orientation of the fin also has a significantly impact on the heat transfer between the cell and air cooling, with the cell temperature rising by 1.5 °C when compared to the half-length of a longitudinal fin. However, the cooling benefit is found to be very modest when the half-fin is placed in various locations on the battery surface (i.e., top, middle, and bottom). Furthermore, compared to the longitudinal fins, the spiral fins reduce the cell temperature by 3.2%, resulting in a 65.6% reduction in material usage.