The achievement comes off the back of a German-funded research project carried out by the company’s KS Gleitlager subsidiary to develop “noble metal-free” electrodes.

The E2ngel project saw KS Gleitlager work with the German Aerospace Centre (DLR) and now-bankrupt electrolyser maker McPhy to qualify the new technology.

Rheinmetall said the DLR Institute of Technical Thermosystems tested several variants, while McPhy trialled them to ensure suitability for use in its alkaline electrolysers.

It claims the innovation will reduce green hydrogen production costs by reducing capital costs, while also “doubling” power density and improving efficiency by more than 10%.

This could tackle one of the main constraints holding back alkaline electrolysers. While already cheaper than rival technologies, their relatively low power density means they need bigger stacks and more materials for the same hydrogen output.

The new electrodes would allow more hydrogen to be produced from smaller, cheaper equipment without relying on scarce precious metals.

Dr Karsten Lange, head of the E2ngel project, said, “The use of our innovative electrode technology will make electrolyser systems more powerful and efficient than they are today.”

Now, Rheinmetall plans to bring a pilot production line at its St Leon-Rot site by 2027. The production line will support electrodes of up to two metres for “multi-megawatt” electrolyser systems.

The firm has not said which electrolyser OEMs will pilot the technology in commercial systems. After McPhy’s insolvency, the French firm’s core assets were acquired by Belgium’s John Cockerill.

At the time of the acquisition, John Cockerill claimed by combining its alkaline cells with “select” McPhy components, the company expects a 10–15% “competitive advantage” over current models.