A battery cell assembly, a heat exchanger, and a method for manufacturing the heat exchanger are provided. The heat exchanger includes a rectangular-shaped sheet having first and second rectangular-shaped sheet portions coupled together at a bent edge such that the sheet portions are disposed proximate to one another. Outer edges of the first and second rectangular-shaped sheet portions are coupled together such that an interior region is formed between the first and second rectangular-shaped sheet portions. The bent edge has first and second apertures extending therethrough. The heat exchanger further includes a first inlet port disposed on the bent edge over the first aperture, and a second outlet port disposed on the bent edge over the second aperture, such that fluid can flow through the first inlet port and into the interior region and then through the outlet port.