A battery cell assembly is provided. The battery cell assembly includes a cooling fin having a rectangular-shaped aluminum plate, a tube, and a flexible thermally conductive sheet. The plate has a first side and a second side. The tube is coupled to the first side of the plate and extends on at least first, second, and third peripheral edge portions of the plate. The flexible thermally conductive sheet is disposed on the first side of the plate. The battery cell assembly further includes a battery cell disposed against the flexible thermally conductive sheet of the cooling fin.