Low Cost Bipolar Plates for Large Scale PEM Electrolyzers

PEM electrolysis is a promising technology for large scale storage of surplus electricity, though it is still costly mainly due to the manufacture of large area and high purity Ti bipolar plates (BPP). In this work we have developed an Au/Ti coating deposited by electrodeposition/thermal spraying on stainless steel BPP. The coating was physically characterized with SEM and electro-chemically evaluated in simulated anode conditions. Interfacial contact resistance (ICR) vs. compaction pressure measurements showed that the coating is highly conductive. It successfully protected the stainless steel substrate from corrosion. However, the Au modification detached after 6 h of application of a potential of 2 V vs. RHE. Consequently the Au modification has to be replaced by either another precious metal or a corrosion resistant electro-ceramic. The coating reported herein could have a large impact on the cost of PEM electrolyzers for large scale electricity storage from renewables.