High-Performance Fuel Cells with a Plasma-Etched Polymer Electrolyte Membrane with Microhole Arrays

Interface engineering based on the design and fabrication of micro/nanostructures has received much attention as an effective way to improve the performance of polymer electrolyte membrane (PEM) fuel cells while using the same materials and quantity. Herein, we fabricated spatially hole-array patterned PEMs with different hole depths using both the plasma etching process and a polymeric stencil with 40 μm-sized apertures. This novel technological approach exhibited high pattern fidelity over a large area and controllability in the pattern depth while excluding the problems of contact-based conventional patterning processes. All the membrane electrode assemblies (MEAs) with the patterned PEMs with an etch depth of 4 μm (PE4-MEA), 8 μm (PE8-MEA), and 12 μm (PE12-MEA) showed higher performance than the reference MEA with a pristine PEM. Among the modified MEAs, the PE8-MEA showed the highest performance enhancement because of the locally thinning effect of the PEM, geometrically favorable features for mass transport, and increased interfacial contact area between the PEM and the catalyst layer.