Zr‐Based Thin‐Film Metallic Glass for Bipolar Plate in Proton Exchange Membrane Fuel Cells

Many researchers have tried to use metallic glass alloys in bipolar plates because of their unique properties such as their higher mechanical strength and corrosion resistances, recently. Thin-film metallic glasses (TFMGs), herein, are coated on an austenitic stainless steel (AISI 316L) plate to enhance the corrosion properties of the metallic bipolar plate. A crystallized alloying target with the composition Zr63.9Al10Cu26.1 and a grain size of less than 1 μm is prepared by consolidating the amorphous powder at 800 °C for 30 min. Also, TFMGs are coated on the AISI 316L plate using direct current (DC) magnetron sputtering system. The contact resistance of the TFMG is decreased by 24 mΩ cm2 by controlling the surface roughness of the AISI 316L plate. The corrosion current densities of the TFMGs are less than 1 μA cm−2 under both anodic and cathodic conditions, and there are no changes of the current density in the range of potentials of 0.6–1.2 V which corresponds to the operating conditions of a proton exchange membrane (PEM) fuel cell. Based on this result, it is believed that these TFMGs can be a potential candidate coating materials for metallic bipolar plate in PEM fuel cell.