A novel compact battery thermal management system comprising phase change material, mini-channels, and fins suitable for EV battery packs

In large Li-ion prismatic cells, which are widely being developed for the battery packs of electric vehicles, non-uniform heat generation occurs during charging/discharging at high rates. Therefore, a particular design of a battery thermal management system (BTMS) is required to provide variable cooling effects for different regions of a large prismatic cell. This study proposes a compact BTMS design by applying phase change material and a combination of mini-channels and fins that can control the temperature of a prismatic cell effectively and uniformly, even when the heat is not generated uniformly in the cell. In addition, the role of the fin structure is investigated by 3D simulation of the proposed hybrid BTMS with eight different fin-types (three flat types with dissimilar surface areas, two ribbed types with dissimilar rib widths, one perforated type, and two wavy types with dissimilar wave direction). The results demonstrate that the best cooling performance is achieved in the cases with wavy fins, despite their less surface area relative to the case with large flat fins. In these cases, at the end of discharging period with 2 C, the average temperature of the cell is <310 K, while the maximum temperature difference on the cell's faces is <2 K.