Rotary targets used to coat PEM electrolyzer components.
Hydrogen is widely viewed as a promising source of “green” energy because when burned or used, it produces only water and not carbon dioxide. But for advocates of clean energy, of equal importance is the method by which hydrogen fuel is actually produced.
One of the most effective options for carbon-free hydrogen production is electrolysis, a process that uses electricity to split water molecules into hydrogen and oxygen. Depending on the electricity source, electrolysis can result in zero or near-zero greenhouse gas emissions.
Hydrogen production via electrolysis is conducted using an electrolyzer, comprising an anode and a cathode separated by an electrolyte. Of particular interest to many hydrogen producers are polymer electrolyte membrane (PEM) electrolyzers, also sometimes known as proton exchange membrane electrolyzers. These offer specific advantages in efficiency, speed, power density, and the ability to yield high-purity hydrogen.
The challenge presented by PEM electrolyzers, however, is high upfront cost resulting from the need to use rare and expensive materials. These materials take the form of precious metals that, when applied as thin-film coatings to particular components, maximize the unit’s overall performance.
As examples, the bipolar plate (BPP) in a PEM electrolyzer can be coated on both sides by platinum or gold, while the porous transport layer (PTL) is often coated with platinum. These metals improve electrical conductivity, enhance corrosion protection, and prevent hydrogen embrittlement.
The bipolar plate from a PEM electrolyzer, which can be coated with platinum and gold through physical vapor deposition.
The metal coatings, applied via physical vapor deposition (PVD), save PEM electrolyzer manufacturers millions of dollars over time by maximizing both operational effectiveness and lifespan. At the same time, they make up the bulk of the total cost of ownership and must therefore be optimized to the highest degree possible.
Materion and its longtime partner VON ARDENNE offer a turnkey solution. VON ARDENNE’s HISS|600 PVD equipment is highly suitable for PEM electrolyzer component coating, while Materion offers both high-quality PVD rotary sputtering targets that work well in VON ARDENNE equipment and decades of precious metal management experience. The two companies also offer dedicated shield and carrier design within PVD equipment, which in combination with proper material selection and pre-treatment for chemical cleaning and refining further increases precious metal utilization.
In addition, VON ARDENNE provides PVD coating solutions for both PEM electrolysis and PEM fuel cells, backed by extensive in-house R&D and analysis capabilities along with coating services. Their proven experience, know-how, and track record in scaling PVD coatings into GW scale have been valuable for large-area, high-volume precious metal sputter coatings. That’s one reason why the company sold the first-ever 24/7 PVD production tool of GW scale to the PEM electrolyzer industry – an HISS|600 commissioned in early 2024.
Materion offers both cast/bond and sprayed precious metal rotary targets. Advantages of cast/bond include smaller loss of precious metal, higher density, and lower amounts of oxygen. Sprayed targets are perfect for smaller thicknesses and entail both a lower starting financial commitment and the ability to handle high-power loads.
Materion also leverages its supply chain and machining experience to produce backing tubes that meet tight tolerances at tube endings. Spent targets and used backing tubes can be sent to Materion for recycling and reclaim, leading to even higher cost optimization.
For more information, please reach out to Materion’s Christoph Simons (Christoph.Simons@materion.com) and VON ARDENNE’s Alexander Wemme (Wemme.Alexander@vonardenne.com). You can also visit Materion’s website for information on sputtering targets and evaporation materials.