Improving the Performance of PEM Fuel Cells: Form a Patterned Hydrophobic Catalyst Layer

In this study, we report a high-performance patterned hydrophobic catalyst layer suitable for efficient PEM fuel cells, thanks to alternating hydrophobic channels. Using the shadow mask spraying process, we produced a layer of dot-array and linear hydrophobic patterns on the ordinary cathode catalyst layer. The alternating hydrophobic channels enhance the transport of liquid water/air on the catalyst layer surface and improve the performance of the proton exchange membrane fuel cell. The performance of cells with dot-array hydrophobic catalyst layer (DHCL), linear hydrophobic catalyst layer (LHCL), and surface hydrophobic catalyst layer (SHCL) was compared with that of the ordinary catalyst layer (OCL). Their performance was characterized by in situ electrochemical methods such as electrochemical impedance spectroscopy and polarization curve. The results show that the output power of LHCL is 0.14 W higher than that of OCL, which is approximately 49% improvement. A stable water/gas channel is formed on the cathode catalyst layer surface, so that the mass transfer can be continuously and stably carried out. This work provides a new idea for the water management in fuel cells.