Electrolyzer coatings

Electrolyzers enable a sustainable society

Green hydrogen production from renewable energy sources with water electrolysis is one of the most promising technologies to enable a sustainable energy system and society. Electrolyzers produce hydrogen by splitting water into oxygen and hydrogen. The electrolyzers are composed of different parts depending on the electrolysis technology used. Most common today are proton-exchange membrane (PEM) electrolyzers, and alkaline electrolyzers. Solid-oxide and anion exchange membrane (AEM) are other electrolyzers types under development.

High-performing noble metal coatings for PEM electrolyzers

Metal separator plates, porous transport layers (PTLs) and current collector plates are core stack components in PEM electrolyzers. These components need to last up to 80 000 hours in the challenging environment inside the electrolyzer with maintained properties

A typical PEM electrolyzer stack contains 100-200 electrolyzer cells (“repeating unit”).

By coating the plates and PTLs with high-performing PVD noble metal coatings, the electrolyzer stack achieves high energy efficiency and long durability, both of which are crucial for the electrolyzerʼs key metrics and market competitiveness. The noble metals provide outstanding protection, low contact resistance and excellent adhesion for highest possible durability and performance.

The thicknesses of PVD coating layers are highly tunable, which means noble metal coatings can be precisely controlled and adapted to optimize anode and cathode properties, as well as coating cost. The coatings can be further enhanced with basecoat layers when needed.

INLINECOATER™ PVD systems for cost-efficient noble metal coatings

With the multi-chamber INLINECOATER™ PVD systems, one or several noble metals can be deposited on either side of the substrate. Single, or simultaneous double-sided coatings can be applied in each coating chamber, and different materials can be applied in separated chambers, for optimal productivity and cost-efficiency.

The INLINECOATER™ architecture also enables efficient use of coating masks to ensure precise coating areas and optimal recycling of noble metal materials.

Electrolyzers | Platinum coatings

PVD platinum coatings offer excellent protective and performance enhancing properties thanks to good adhesion, coverage and precise control of thicknesses.

The main purpose of the platinum coatings is to reduce contact resistance and prolong longevity of the electrolyzer system by preventing oxidation of the electrolyzer separator plates in the aggressive electrolyzer environment.

Platinum coatings can be applied in extremely thin layers with PVD, from a few nm and up.

Key coating benefits

• Premium durability
• Low, stable interfacial contact resistance (ICR)

Electrolyzers | Gold coatings

PVD gold coatings, like all noble metal coatings, offer excellent protective and performance enhancing properties thanks to good adhesion, coverage and precise control of thickness. Gold is often used as a baseline for premium applications where a low contact resistance is needed to achieve optimal performance.

The main purpose of the gold coating in an electrolyzer is to lower the contact resistance on the cathode side of the electrolyzer separator plates, and to prevent oxidation in the aggressive electrolyzer environment.

Gold coatings also protect the electrolyzer plates from hydrogen uptake. Without a protective coating the small hydrogen atoms can permeate the substrate and cause hydrogen embrittlement – a serious safety hazard and cause for premature system failure.

Gold coatings can be applied in extremely thin layers with PVD, from 1 nm and up. 

Key coating benefits

• Premium durability
• Low, stable interfacial contact resistance (ICR)
• Embrittlement protection (basecoat possible for further protection)

Electrolyzers | Iridium coatings

PVD iridium coatings, like all platinum-group metal coatings, offer excellent protective and performance enhancing properties thanks to good adhesion, good coverage and precise control of thickness. This noble metal is more difficult to handle with other coating technologies than PVD.

Iridium coatings are known to offer exceptional corrosion and oxidation protection and prolonged lifespan of parts in extreme environments and offer very low contact resistance for optimal performance in an electrolyzer cell.

Iridium coatings can be applied in extremely thin layers with PVD, from a few nm and up.

Key coating benefits

• Exceptional corrosion and oxidation protection
• Premium durability
• Low, stable interfacial contact resistance (ICR)

Electrolyzers | Dense iridium oxide

Our dense iridium oxide coating provides outstanding catalytic properties at very low iridium loading (mg/cm²) and excellent durability, owing to a high-quality crystal structure combined with strong adhesion and cohesion. Like metallic iridium, the dense iridium oxide is conductive and enables very low interfacial contact resistance.

Iridium oxide is a state-of-the-art material for PEM electrolyzer components because of its capability to enhance the oxygen evolution reaction (OER), resulting in optimal hydrogen production.

By coating porous transport layers (PTLs) with Impact Coatings’ dense iridium oxide, they become porous transport electrodes (PTEs) with catalytic properties. This solution reduces the need to apply excessive amounts of iridium on the membrane, therefore leading to significant cost savings.

Our dense iridium oxide coating can be applied as a very thin layer by PVD, corresponding to an iridium loading of 0.1 mg/cm². Higher loadings are possible upon request.

Key coating benefits

• Catalytic functionality
• Exceptional stability and corrosion protection
• Premium durability
• Low, stable interfacial contact resistance (ICR)

Technical overview