In order to reduce the cost, weight and volume of bipolar plate, more attention is being paid to the use of metallic materials, among which 316L stainless steel is quite attractive as bipolar plate material for proton exchange membrane fuel cell (PEMFC). In this study, metallic Ta was coated on 316L stainless steel using physical vapor deposition (PVD) to enhance the corrosion resistance of based material. Simulative working environment of fuel cells was applied for testing the corrosion property of uncoated and coated 316L stainless steel. X-ray diffraction (XRD), scanning electron microscopy (SEM) and electrochemical methods (potentiodynamic and potentiostatic) were used to characterize for the Ta-coated and uncoated 316L stainless steel. Results showed that 316L stainless steel with Ta-coated had better anticorrosion property. Corrosion resistance of Ta-coated 316L stainless steel was significantly increased in 0.5M H2SO4 and 2ppm HF at 80ºC than that of uncoated 316L stainless steel. Moreover, corrosion currents of Ta-coated 316L stainless steel in both simulated anode (bubbled with H2) and cathode (bubbled with air) conditions were larger than those of uncoated 316L stainless steel.
Keywords: proton exchange membrane fuel cell (PEMFC); Bipolar plate; 316L stainless steel; Corrosion resistance; Corrosion current