Review on Electric Resistance in Proton Exchange Membrane Fuel Cells: Advances and Outlook

Improving fuel efficiency and performance in proton exchange membrane fuel cells is closely linked to reducing electric resistance. This review discusses the vital role, behavior, and methods to reduce electric resistance in fuel cells. We particularly focus on how electric resistance affects cell polarization loss and overall performance. We summarize key parameters, prediction formulas, standard values, and testing methods for both bulk resistance and contact resistance. A significant part of the review looks at often-overlooked factors like flow field design, clamping pressure, surface properties, and substrate material. The unique "channel/rib" design on the bipolar plates surface has a major impact on electric resistance. Research shows a balance between rib/channel ratios, clamping pressure, and resistance values. While narrower ratios help reduce contact resistance, they can increase bulk resistance and overall cell resistance, affecting voltage outputs. There's an ideal clamping pressure that offers the best balance between resistance and performance. Further, this review underscores the significance of material selection, flow field design, clamping pressure, and surface treatments in resistance management. Designs like serpentine flow fields and materials such as carbon paper are noted for their lower resistance characteristics. Synthesizing these insights, we propose coherent strategies to enhance cell performance by reducing electric resistance through improved fuel cell design. Conclusively, we analyze the challenges and future perspectives in achieving minimal electric resistance and maximal cell performance. Potential avenues for future research are identified, with an emphasis on nanomaterials, advanced fabrication techniques, experimental methodologies, numerical modeling, flow field design, and operational optimization.