Conventional flow-field designs of proton exchange membrane fuel cells: Design considerations, challenges, and opportunities for improvement

Flow-field design is a primary determinant of proton exchange membrane fuel cell (PEMFC) performance, governing reactant distribution and the removal of water and heat across the active area, and thereby influencing cell efficiency, durability, and cost. Existing reviews largely address the performance, materials, and manufacturability of conventional flow-field designs separately and qualitatively; moreover, because the performance of each design varies with active area and operating conditions, direct comparison across independent studies is difficult. This review instead synthesises experimental and numerical results for the three conventional geometries, parallel, serpentine, and interdigitated, using matched within-study comparisons referenced to the parallel design, so that each performance difference reflects geometry rather than differences between studies, and links each geometry to its material and fabrication constraints. Relative to the parallel design, serpentine and interdigitated designs show higher peak power density, improved water removal, and, in most studies, more uniform reactant distribution, associated with their stronger convective transport. These differences come at the cost of a substantially higher pressure drop, whose magnitude and even ordering depend strongly on cell scale and operating regime. Flow-field selection thus emerges as an inherent trade-off among mass transfer, parasitic loss, and manufacturability. Building on this synthesis, the review identifies pathways toward hybrid and optimised designs and integrated techno-economic evaluation to support large-scale PEMFC deployment.