Structural design of microporous layer to mitigate carbon corrosion in proton exchange membrane fuel cells

Unsteady-state operating conditions of proton exchange membrane fuel cells (PEMFCs) will cause local ultrahigh potential, resulting in carbon corrosion of the gas diffusion layer (GDL). To mitigate performance degradation, this work prepared a novel wavy microporous layer (MPL) by gelatinous MPL slurry on the surface of GDL. By morphology characterization, GDL containing common MPL (com-GDL) exhibited serious structural destruction. In contrast, GDL containing wavy MPL (wavy-GDL) revealed high structural stability. Due to the wavy shape and rough surface, the corrosion region of GDL was transferred from MPL to the macroporous substrate. In the electrochemical testing of the samples, the performance of fresh wavy-GDL was higher than that of fresh com-GDL. After being corroded, the performance of the com-GDL was reduced by more than 20%. While the degradation of the wavy-GDL was less than 10%, realizing effective mitigation of corrosion. In summary, this paper pointed out a novel strategy to improve the durability of PEMFCs. The findings are helpful to promote the carbon corrosion mitigation strategy for other devices at high potential.