Low-Cost and Durable Bipolar Plates for Proton Exchange Membrane Electrolyzers

Area of Science:

• Materials Science
• Electrochemistry
• Chemical Engineering

Background:

• Proton exchange membrane (PEM) electrolysis is crucial for sustainable hydrogen (H2) production.
• High capital costs of titanium bipolar plates (BPPs) hinder large-scale PEM electrolyzer adoption.
• Cost reduction and efficiency are key challenges in H2 production.

Purpose of the Study:

• To investigate the use of stainless steel BPPs coated with niobium (Nb) and titanium (Ti) as a cost-effective alternative.
• To evaluate the protective and conductive properties of Nb/Ti coatings for PEM electrolysis applications.

Main Methods:

• Coating of stainless steel BPPs using magnetron sputtering physical vapor deposition (PVD) for Nb and vacuum plasma spraying (VPS) for Ti.
• Characterization of coating properties via scanning electron microscopy (SEM), atomic force microscopy (AFM), X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (XPS).
• Durability testing of coated BPPs under simulated anode conditions for over 1000 hours.

Main Results:

• A 50 μm Ti coating effectively protected the stainless steel substrate from corrosion.
• A significantly thinner Nb layer (approx. 1 μm) reduced contact resistance by nearly an order of magnitude.
• Nb/Ti-coated stainless steel BPPs demonstrated stability and durability exceeding 1000 hours in harsh anode environments.

Conclusions:

• Stainless steel BPPs coated with Nb/Ti offer a promising, cost-effective solution for PEM electrolysis.
• These coated BPPs can potentially enable large-scale, sustainable hydrogen production from renewable energy sources.
• The developed coating technology addresses critical challenges in capital cost and component durability for electrolyzers.