Investigation of Liquid Water Behaviors in Carbon Paper GDL for PEMFCs by Soft X-Ray Radiography Available to Purchase

Liquid water behaviors in the porous gas diffusion layer used for PEMFCs were investigated by high-resolution soft X-ray radiography. We observed water evaporation process from the soaked carbon paper GDL and showed the gradual disappearance of liquid water with spatial inhomogeneity. The visualization of liquid water revealed that thin water film was retained in the GDL. This was also observed in the operating fuel cell. Our soft X-ray observation suggests that this thin water film formed in the carbon paper GDL possibly caused increase in the toutuosity of the GDL, resulting in deterioration of cell performance due to less mass transport in fuel cells.