Fraunhofer Institute for Microstructure of Materials and Systems IMWS
Electrolysers and fuel cells play a central role in the energy transition. With the growing demand for green hydrogen and the increasing electrification of industrial processes, there is mounting pressure to produce these technologies cost-effectively, in high quality, and in large quantities. While production is already scaling up to the gigawatt level, there is still a lack of testing methods that meet the requirements of modern production lines for electrochemical systems. This is where the “MAGIQ” project of the Fraunhofer Institute for Microstructure of Materials and Systems IMWS in Halle (Saale) comes in: It aims to open up new ways to efficiently and precisely evaluate the quality of PEM electrolysis and fuel cell stacks.
“MAGIQ – Magnetic Field Imaging with AC Excitation for Quality Testing of PEM Electrolysis and Fuel Cell Stacks” aims to develop a completely new, fast, and imaging test method for quality assurance of modern cell stacks. These stacks form the heart of electrolysers and fuel cells and account for a significant portion of the total cost. While their manufacture is increasingly being transferred to automated mass production worldwide, there is still no practical, spatially resolved testing method that can be used immediately after production. Previous methods always require actual electrolyser or fuel cell operation to record electrical characteristics – a time-consuming and costly process that prevents routine quality control.
Therefore, a joint project between DENKweit GmbH and Fraunhofer IMWS aims to develop a measurement method that visualizes current density and conductivity distributions within fully assembled stacks without requiring them to be operational. The key lies in measuring magnetic fields generated by high-frequency alternating current. At frequencies in the kilohertz range, so-called displacement currents flow in the cells, which do not require electrochemical reactions and yet provide information that is proportional to that which would be available in later real operation. This makes it possible to reliably identify defects and electrical inhomogeneities at the end of production.
Both partners contribute their technological expertise. DENKweit GmbH develops highly sensitive magnetic field sensor technology, data visualization methods, and control and evaluation software. Fraunhofer IMWS is developing the test bench with the frequency-variable high-current source that will be used for the analyses. In addition, models are being developed that allow reliable conclusions to be drawn from the measurement signals about current density distributions and defects – with special consideration given to frequency-dependent effects such as the skin effect. This describes the phenomenon whereby alternating current (AC) in a conductor tends to concentrate on the surface of the conductor instead of flowing evenly through the entire cross-section. In electrolysis and fuel cells, this can influence the measurement results, especially at high frequencies. In addition, the institute qualifies the method for integration into existing analysis concepts and evaluates its measurability for real industrial applications.
The innovative approach of applying magnetic field imaging to alternating current excitation opens up completely new possibilities compared to previous methods. While segmented current sensors or classic magnetic field measurements always require real operation, the project creates the basis for electrically characterizing stacks outside of electrochemical test benches for the first time. “This creates a solution that can significantly support technological progress in the mass production of electrolysis and fuel cell systems. The process has the potential to enable fast, contactless, and spatially resolved quality testing directly after assembly for the first time worldwide, thereby reducing costs, avoiding rejects, and significantly increasing the reliability of the systems,” says project manager Dr. Volker Naumann.
The planned prototype measurement setup will lay the foundation for subsequent product development and possible use in highly automated production lines. The project is thus positioning itself as an important building block for technological progress in the hydrogen economy and for the sustainable energy supply of the future.
(18.11.2025)