Determination of the porosity and its heterogeneity of fuel cell microporous layers by X-ray tomographic microscopy

Advancing polymer electrolyte fuel cell technology includes the rational design of microporous layer (MPL) coating on gas diffusion (GDL), where porosity and morphology an operation-relevant size scale are still largely undetermined hinder further developments. Here, 15 commercially available GDLs with MPL coatings from three major manufacturers (seven Freudenberg, four Sigracet® SGL CeTech materials) were characterized by X-ray tomographic microscopy. An extensive set structural parameters for MPLs presented, including total porosity, microporosity, heterogeneity thickness heterogeneity. The analyses show that tend to have lowest while highest porosity. Furthermore, Freudenberg H23 materials heterogeneity, CX materials’ most heterogeneous. Many commercial MPLs, expected be homogeneous, a gradient microporosity in direction. classified into five distinct classes based heterogeneities. This classification detailed data presented support understanding performances different types. comprehensive also serve as realistic input values material modeling studies.