Lab and industry collaborate to develop the next generation of advanced electrode materials - Part 1
About the Author
Alise-Valentine Prits is a PhD researcher in sustainable energetics at the University of Tartu and a Junior Scientist at Stargate Hydrogen. Her work focuses on developing the next generation of advanced electrode materials for alkaline water electrolysis, contributing to the advancement of green hydrogen technologies. With a strong foundation in chemistry and materials engineering, Alise-Valentine combines academic insight with hands-on experience in R&D. She is also a teacher and is passionate about making science accessible to everyone.
Introduction
This two-part article by guest contributor Stargate Hydrogen aims to provide a practical overview of the findings from the study "Electrochemical characterisation of Raney nickel electrodes for alkaline water electrolysis: From laboratory to industrial scale" by Alise-Valentine Prits, et. al. Published with unrestricted access in the International Journal of Hydrogen Energy.
You can access the full study here.
Why is it important to study advanced electrode materials?
Electrode materials play a central role in the efficiency and cost of alkaline water electrolysis (AWE). They directly influence how much energy is needed to split water into hydrogen and oxygen by lowering the activation energy of the reactions. The more effective the catalyst, the less energy is wasted, and the more viable green hydrogen becomes.
While noble metals like platinum, iridium, and ruthenium offer excellent performance, their high cost and limited availability make them impractical for large-scale AWE systems. That’s why most commercial electrolysers rely on more affordable nickel-based electrodes, even though they come with a trade-off in efficiency.
To bridge this gap, researchers are actively developing nickel-based advanced electrode materials that offer better performance without relying on scarce elements. Raney nickel is one such example already used in industry, but there is still room for improvement.
Aiming to drastically reduce the cost of green hydrogen production, Stargate Hydrogen’s scientists are developing novel advanced electrode materials, which they call Stardust. A completely new class of electrolysers: ceramics-based alkaline electrolysers, that have high current densities, and high efficiencies, yet contain no precious metals. This results in significantly lower hydrogen production costs and makes the electrolysers affordable for the heavy industries which are one of the largest emitters of CO2 in the atmosphere.
What makes studying advanced electrode materials challenging?
One of the main challenges in developing new advanced electrode materials is that laboratory testing conditions often differ significantly from those used in industrial AWE systems. As a result, findings from academic research may not always translate directly to real-world applications.
In many academic studies, electrodes are tested using three-electrode setups with small electrode areas, no separator, and no electrolyte circulation. These experiments are typically conducted at room temperature and atmospheric pressure, using diluted KOH solutions (e.g., 0.1 M or 1 M), and often benchmarked at low current densities around 10 mA/cm².
In contrast, industrial AWE systems operate under much harsher conditions: concentrated KOH (~30%wt), elevated temperatures (around 80 °C), and pressures up to 30 bar. Modern stacks also run at much higher current densities – up to 1 A/cm². These differences are especially important in durability studies, where current density and temperature can strongly influence electrode lifetime and performance.
Another factor is electrolyte purity. In lab settings, KOH is often purified to remove impurities like iron, which can affect catalytic activity. However, in industrial systems, iron is commonly present due to leaching from stainless steel components. This means that testing materials in iron-free conditions may not reflect how they will behave in actual electrolysers.
Together, these differences highlight why it is essential to design lab experiments that better reflect industrial conditions, especially when the goal is to evaluate materials for real-world use.
Image ©Stargate Hydrogen
What parameters matter the most when studying advanced electrode materials?
To generate results that are relevant for industrial applications, several key factors should be carefully controlled and reported during lab-scale testing:
Temperature: Temperature has a major impact on performance. In this study, increasing the operating temperature from room temperature to 80 °C reduced cell voltage by up to 240 mV at 300 mA/cm². This is mainly due to improved electrolyte conductivity. However, since catalyst behaviour can vary with temperature, testing at elevated temperatures is essential for industrial relevance.
Pressure: Increasing pressure from 1 to 6 atm reduced the voltage by about 40 mV at 300 mA/cm² in this study. While this shows a measurable effect, the impact of pressure was smaller compared to the effect of temperature. This observation is consistent with previous research, which suggests that higher pressure can reduce gas bubble size and minimise bubble blockage, thereby lowering resistance.
Electrolyte composition: In this study, using a more concentrated KOH solution (26% vs. 1 M) led to lower voltages for the oxygen evolution reaction (OER) and the full electrolysis cell. This improvement is mainly due to increased ionic conductivity. For the hydrogen evolution reaction (HER), the effect of KOH concentration was minimal.
The presence of iron in the electrolyte also had a clear activating effect – this was observed in both the three-electrode and two-electrode setups. Adding a small amount of iron (0.1 mM Fe³⁺) reduced OER overpotentials by up to 80 mV and improved full-cell performance, especially at higher current densities. This enhancement is attributed to the formation of catalytically active nickel-iron surface species for OER, and the formation of Fe dendrites leading to increased surface area or the prevention of the formation of deactivating Ni hydride for HER.
Because iron can significantly influence performance, it is important to monitor and control its concentration during testing. This is particularly relevant when the goal is to evaluate advanced electrode materials under conditions that reflect real industrial use, because industrial electrolysers typically include stainless steel components from which iron can leach into the electrolyte over time.
Cell configuration: The study demonstrates that cell design can influence the results. The setup that mimicked the industrial stack more closely by including elastic elements showed higher voltages than the cell without the elastic elements. Yet the performance of this cell was also closer to the performance of the stack. This difference was linked to increased ohmic resistance and variations in flow dynamics. It’s therefore important to define the goal of the measurement and choose the cell configuration accordingly.
Recommendations from the authors
To ensure industrial relevance, the authors recommend performing measurements at temperatures above 70 °C using concentrated KOH solutions (~7 M). The iron content in the electrolyte should be recorded and, where possible, controlled. If the setup allows, testing at pressures above 5 atm is also advised. These conditions reflect the real-world operation of alkaline electrolysers and align with EU testing protocols.
Working Together
Stargate Hydrogen take pride in bringing technical expertise and industrial realism to every electrolysis project. If you’re looking to kickstart hydrogen production, get in touch with us today. We’re here to help turn proven lab research into real-world hydrogen output.
To find out more about Stargate Hydrogen, visit www.stargatehydrogen.com.
Read Part 2 of the article here!