Green hydrogen is considered a key technology for the decarbonization of industry. Until now, a breakthrough has been hindered by efficiency, cost, and scalability issues in production. This is set to change with the high-temperature electrolysis stack developed by Dr. Mihails Kusnezoff, Dr. Stefan Megel, and Dr. Sindy Mosch of the Fraunhofer Institute for Ceramic Technologies and Systems IKTS in Dresden, who were awarded the 2026 Joseph von Fraunhofer Prize for their work.

High-temperature electrolysis is a highly efficient process for producing hydrogen. In this process, water vapor is split into hydrogen and oxygen in an electrolyzer. The advantage: Thanks to the high temperatures, industrial waste heat can be used directly as the energy source for the splitting reaction. This saves on expensive electricity, accelerates the electrochemical reactions, and thus optimizes efficiency.

New Scientific and Methodological Approach by Fraunhofer IKTS

For more than two decades, researchers at Fraunhofer IKTS have been pursuing an extremely ambitious vision: to make high-temperature fuel cells and electrolyzers so powerful, robust, and economical that they can not only support the energy transition but also significantly accelerate it. “From the very beginning, our goal was to build a bridge between electrons and molecules,” says Dr. Mihails Kusnezoff, Head of the Materials and Components Department and Head of the Energy Business Unit at Fraunhofer IKTS. The Fraunhofer IKTS team’s approach differs significantly from that of many competitors: Instead of pursuing separate concepts for electrolysers and fuel cells, the researchers developed a system that equally addresses both operating environments. This was a major challenge, because “while fuel cells require low resistance and high voltages, electrolysis demands long-term stable, nearly thermoneutral operation with minimal temperature gradients,” explains Dr. Mihails Kusnezoff.

A Stack Suitable for Mass Production and Universal Use

In the lab, the researchers developed new materials for the electrolyte and electrodes, optimized microstructures, and used them to build high-performance cells. “It is only the combination of many cells that creates the so-called stack—the heart of the system. It enables the necessary scaling to produce hydrogen in industrial quantities,” explains Dr. Sindy Mosch, a researcher in the Materials for Printed Systems research group at Fraunhofer IKTS. The technical breakthrough was ultimately achieved through a combination of material innovation, design optimization, and consistent industrialization. “We had to learn to consider electrochemical, thermal, and mechanical effects as part of an integrated system. Only through the precise interplay of microstructure, sintering behavior, and protective coatings were we able to develop a cell that functions reliably for years, both under harsh electrolysis conditions and in fuel cell mode,” says Dr. Sindy Mosch.

The Fraunhofer IKTS stack operates stably within an extended temperature range of 750 to 850 degrees Celsius—a decisive factor for the service life of an electrolyzer. Within this operating temperature range, not only can water vapor and CO2 be converted into synthesis gas via electrolysis, but various fuels such as natural gas, biogas, methanol, ethanol, or even green ammonia can be used in fuel cell mode to generate electricity.

From the Lab to the Factory: Pilot Production in Arnstadt

At the same time, the team addressed industrial scaling by redesigning the metallic bipolar plate for efficient manufacturing in a single pressing step and developing scalable coating processes for electrodes as well as contact and protective layers. “It was clear to us: a technology only contributes to the energy transition if it works on the factory floor and not just in the lab,” emphasizes Dr. Stefan Megel, group leader of Ceramic Energy Converters at Fraunhofer IKTS.

Technology’s Maturity Convinces the Industry

The technology’s industrial maturity also convinced the industry: thyssenkrupp nucera identified the developed stack as a particularly efficient and promising solution in the field of high-temperature electrolysis. Within just fourteen months, Fraunhofer IKTS set up an initial semi-automated pilot production line at its Arnstadt site as the basis for further upscaling in collaboration with its industry partner, thyssenkrupp nucera. “The pilot production demonstrates that our stacks are not only scientifically leading but also industrially manageable and economically producible—all the way up to a gigawatt-capable factory,” said Dr. Stefan Megel.

Key Technology for Industrial Decarbonization

The stack development at Fraunhofer IKTS has not only set new standards in efficiency and technological flexibility but also lays the foundation for the industrial use of electricity and waste heat for highly efficient hydrogen and synthesis gas production. In this way, the Fraunhofer IKTS team is making a direct contribution to the global energy transition while simultaneously strengthening Germany’s competitiveness as a business location.

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