Acceleration of through-plane water removal in polymer electrolyte fuel cell by channel hydrophilization and electrode perforation

To alleviate water flooding in cathode electrodes of polymer electrolyte fuel cells (PEFCs), it is essential to design the optimum channel/electrode structure for rapid water removal. This study presented a novel hybrid structure with the channel hydrophilization and electrode perforation for accelerating the through-plane water discharge and demonstrated the effect of its structure on the water transports in the cathode channel and gas diffusion layer (GDL) of a working PEFC with optical and X-ray imaging. The results revealed that the hydrophilization of the channel walls encourages the through-plane water suction form the GDL to the channel. Furthermore, the electrode perforation promotes the in-plane water discharge from the fine porous media to the large penetration grooves and holes. The synergistic effect of these two water transports in the hybrid structure effectively alleviates the flooding in the porous layers and enhances the oxygen diffusibility, resulting in significant improvement of the cell performance.