Lecture
Van Marum Colloquium: Advancing water electrolyzers: component development and lifetime degradation studies at TNO
- Dr. Davide Ripepi (TNO Delft)
- Date
- Monday 15 September 2025
- Time
- Location
-
Gorlaeus Building
Einsteinweg 55
2333 CC Leiden - Room
- CM.3.23
Abstract
In the Clean Industrial Deal, the EU has set up a plan for boosting competitiveness and decarbonisation in Europe's energy-intensive industries. Hydrogen stands as a key component in the EU's strategy to the energy transition, net-zero, and sustainable development, specifically for decarbonising energy intensive industrial processes and the transport sector. The ambitious scale-up scenarios can only materialise if costs reduce and lifetime improves. Thus, durability and lifetime prediction of water electrolysers are critical. At TNO, we leverage our testing infrastructure ranging from lab-scale cells to stacks and systems, to link degradation studies with practical operation.
Part of our work focuses on the development of representative accelerated stress tests (ASTs) that reflect real operational degradation pathways, making them relevant for durability and lifetime assessment. This requires improved understanding of underlying degradation mechanisms and the ability to decouple component-specific degradation contributions, as electrolysers are inherently multi-component devices. To address these challenges, we are developing and integrating electrochemical techniques such as in situ reference electrodes together with material characterization methods to better interpret the behaviour of individual components and support the design of ASTs aligned with real-world conditions.
In parallel, in TNO we also develop components to enable the large-scale water electrolysis technologies. One example is for proton exchange membrane water electrolysis (PEMWE), where the use of Iridium as oxygen evolution (OER) catalyst is a bottleneck for the required GW scale application. Therefore, we use the scalable manufacturing technology spatial atomic layer deposition (sALD) to manufacture electrodes with loadings as low as 0.02 mgIr cm-2 for use in PEMWE. With the use of electrochemical and spectroscopic characterization techniques we show how substrate chemistry and morphology play a more significant role in boosting the performance and stability of these ultra-low loaded electrodes as opposed to increasing the Iridium loading itself.