Enhancement of Water Drainage by Partial Surface Hydrophilizing of the PEFC Gas Diffusion Layer

Abstract

For polymer electrolyte fuel cell (PEFC), control of water drainage is an important issue to supply oxygen to catalyst layer (CL) in high current density operation. The gas diffusion layers (GDLs) have a critical role of water drainage and gas distribution in PEFC. The author's previous studies have showed that hydrophilic treatment of GDL surface decreases water accumulation in GDLs. In this study, enhancement of water drainage was attempted by partial hydrophilizing of the GDL. The GDL surface that touch the rib part was hydrophilized by applying the Nafion solution and drying it. The effect of partial surface hydrophilization on the cell performance was discussed by observing condensed water behavior and measuring cell potential changes using a visualization cell. As a result of the experiment, it was shown that the partial surface hydrophilizing of GDL can improve the water drainage performance.