As the demand for clean hydrogen energy continues to rise, researchers are working to make hydrogen production both more efficient and affordable. One promising approach is anion exchange membrane water electrolysis (AEMWE). This complex term translates into a simple process: produce hydrogen using renewable electricity without relying on critical raw materials such as costly precious metals. However, the performance of these electrolysers depends greatly on a component known as the porous transport layer (PTL).
From a technical point of view, the PTL is positioned between the catalyst layer and the metal plates within the electrolyser. Its role is to help water reach the reaction sites, allow oxygen gas to escape, conduct electricity, and distribute mechanical pressure evenly. If the PTL is poorly designed, trapped gas bubbles can block reaction surfaces, electrical contact may weaken, and the cell can wear out more quickly.
The HYScale researchers investigated a new PTL made from knitted wire mesh. Unlike rigid or foam-based PTLs, the knitted structure behaves like a spring, allowing it to compress evenly during assembly. This flexibility ensures better contact between layers, reduces the risk of membrane damage, and improves the flow of gases and liquid through the system.
When this knitted PTL was added to a standard AEMWE cell:
- The hydrogen production rate (current density) increased by 33%
- The cell required less voltage at high operating power, improving efficiency
- Gas removal and water movement became easier
- Mechanical stress was distributed more evenly, improving durability
The knitted PTL can be produced at a relatively low cost, making it a practical improvement for future hydrogen technologies. This innovation will also support the EU’s development by fostering a competitive, sustainable hydrogen industry and contributing to energy independence and the green transition.
The design of the PTL is led by the German Aerospace Center (DLR), partner of the HYScale project.
