Investigation of Electroplating Trivalent Cr-C on Copper Alloy As Bipolar Plates with Different Current Density in Pemfcs

In this study, the trivalent Cr-C coating was electroplated on copper alloy as bipolar plates because of their excellent electric conductivity and corrosion resistance.  The SEM images showed that the thickness of the coating was about 2 to 13 μm and increased with raised coating current density. The surface morphology at 10 A/dm² is more smooth, no cracks and has high carbon content (46.65 at％). Moreover, the polarization curve with different coating current density (10, 30, 50 A/dm²) represented the coating prepared at 10 A/dm² and 10 minutes possessing the lowest corrosion current density (I_corr=1.9 x 10^-7 A/cm²). At contact resistance measurement, we got value (3.2 mΩcm²) at 10 A/dm² which less than the standard of DOE (20 mΩcm²). The results of single cell test showed better performance (about 338.0 mW/cm²) at 10 A/dm².