Effects of passive films on corrosion resistance of uncoated SS316L bipolar plates for proton exchange membrane fuel cell application

摘要: The effects of passive films on the corrosion behaviors uncoated SS316L in anode and cathode environments proton exchange membrane fuel cells (PEMFCs) are studied. Potentiodynamic potentiostatic polarizations employed to study behavior; Mott-Schottky measurements used characterize semiconductor properties films; X-ray photoelectron spectroscopy (XPS) analyses identify compositions depth profiles films. formed PEMFC under corresponding conditions both behave as n-type semiconductor. film environment has a single-layer structure, Cr is major element (Cr/Fe atomic ratio > 1), Cr/Fe ratio decreases from surface bulk; while bi-layer Fe ratio < 0.5), external layer structure content increases rapidly gradually internal layer. shows better resistance owing high oxide low band bending normal environments.