Effect of Pt Coating on Electrochemical Behavior and Interfacial Conductivity of TA4 Bipolar Plate in Anode Side Environment of Proton Exchange Membrane Water Electrolyzer for Hydrogen Production
Pt coatings were successfully deposited on the surface of TA4 Ti-alloy using the DC pulse magnetron sputtering technique.With the increasing deposition time,the lattice constants of Pt coating in-creased from 0.39112 nm at 5 min to 0.39128 nm at 15 min,correspondingly the thickness increased from approximately 0.29 μm to around 0.95 μm.Electrochemical studies revealed that the open circuit voltage(OCP)of Pt-coated TC4 was approximately 0.77 V higher than that of the plain TA4.With the ex-tension of deposition time,the interfacial electrochemical reaction resistance further increases,as a re-sult,its charge transfer resistance will gradually increase with deposition time as described as below:5.52 × 104,5.91 × 1 04,and 6.1 × 104 Ω·cm2,respectively.Importantly,the Pt coating effectively enhanced and maintained the excellent interface conductivity,as the interface contact resistance(ICR)only exhibit-ed a slight increase after a simulated steady-state polarization testing.In sum,the Pt coating can signifi-cantly enhance the interfacial conductivity of TA4 in the anode side environment of proton exchange membrane hydrogen electrolyzer(PEMWE).