Experimental characterization of the water transport properties of PEM fuel cells diffusion media

► This work presents guidelines to characterize the water transport characteristics of GDL materials for PEM fuel cells. ► An experimental apparatus is designed and used to measure capillary pressure-saturation relationships in GDL materials. ► An experimental apparatus is designed and used to measure relative permeability of GDL materials as a function of liquid water saturation. ► The water transport characteristics of carbon paper Toray 090 are obtained (porosity, capillary pressure curves, absolute permeability, and relative permeability).