More hydrogen!

Marion Merklein, Simon Thiele and their contribution to the energy transition

If the energy transition is to be a success, we need sources of green hydrogen and efficient technologies to use the energy it contains. Mechanical engineer Marion Merklein and process engineering specialist Simon Thiele are researching this field. An interview.

Prof. Merklein, Prof. Thiele, what have you got to do with hydrogen?

Marion Merklein: My field of research is the interface between materials science and mechanical engineering. It involves the forming and mechanical joining processes of metal workpieces such as riveting and shear clinching. Hydrogen is an important topic for me, because I would like to optimize both the development and large-scale production of fuel cells.

Simon Thiele: I work on improving existing electrochemical converters and researching completely new ones. These electrochemical converters are systems such as electrolyzers for manufacturing hydrogen from electricity and water or fuel cells for converting hydrogen into electrical energy further down the line.

Prof. Simon Thiele
Image: FAU/Giulia Iannicelli

Prof. Dr. Simon Thiele studied physics at the University of Freiburg, where he also completed his doctoral degree. In 2011, he became group leader for “Porous Materials” at the Department of Microsystems Engineering at the University of Freiburg and in 2017 he was also appointed group leader for “Electrochemical Systems” at the Hahn-Schickard Institute of Applied Research, Freiburg. Since 2018, he has been Professor of Electrocatalytic Interface Engineering at FAU and head of department at the Helmholtz Institute Erlangen-Nürnberg for Renewable Energy (HI ERN).

Electrolyzers and fuel cells are already in operation. What are the biggest challenges at the moment?

Simon Thiele: The performance of our systems is currently not satisfactory and the costs are also too high. The price of hydrogen needs to go down drastically if we want to make this a success. The USA has set the ambitious goal of bringing the price of hydrogen down to only one dollar per kilo within the next decade. And fuel cells must also become cheaper.

How can this be done?

Simon Thiele: By increasing the efficiency of the processes involved. In addition, future large-scale production must provide significant cost advantages. My working group is carrying out intensive research on new materials and processes, such as the membrane electrode assembly, which plays a central role in both electrolyzers and in fuel cells. At the same time, we need to keep an eye on the overall costs. Electrolysis with acidic polymer electrolyte membranes requires iridium – a very rare and therefore very expensive precious metal. Alkaline electrolyzers could be an alternative, which allow for non-precious metals to be used as catalysts. We are also investigating whether the performance of such converters can be increased by increasing the operating temperature.

Simon Thiele prüft eine Testzelle für die alkalische Elektrolyse.Simon Thiele inspects a test cell for alkaline electrolysis. (Image: FAU/Giulia Iannicelli)


Ms Merklein, what contribution can you make as a materials forming specialist?

Marion Merklein: At the heart of every fuel cell there are something known as bipolar plates, which are ribbed metal plates joined in mirror symmetry. This produces channels that are separated from each other through which hydrogen and oxygen flow, the raw materials for the catalytic reaction. These plates are 700 by 700 millimeters in size and are almost as thin as a piece of aluminum foil. However, these plates still have to be stable enough so that a large number of them can be stacked next to each other in the fuel cell with exactly the same distance between them. As you can imagine, this is quite a challenge.

Marion Merklein
Image: FAU/Giulia Iannicelli

Prof. Dr. Marion Merklein studied materials science and engineering at FAU and was subsequently employed as a research associate at the Institute of Manufacturing Technology (LFT). After completing her doctoral degree in 2001, she headed the “Sheet Metal and Profile Forming” and “Hydroforming” research groups at the LFT. In 2008, she was appointed Professor of Manufacturing Technology at FAU. Marion Merklein is one of the most renowned researchers in the field of forming and joining technology. In 2013, she was awarded the Gottfried Wilhelm Leibniz Prize from the DFG.

How do you overcome this challenge?

Marion Merklein: One the one hand with the correct material – we’re currently looking at titanium, but also steel and aluminum as cheaper alternatives. And of course, the shape of the workpiece plays a decisive role. Corrugating the foil increases its stability – just like when you fold a piece of paper in the same way. This is just the first step, however. Being able to reproduce this process at high speed with minimal tolerances is decisive for subsequent volume production. This means we are not only looking at the shape of the plates, but we will shortly set up a complete production line for fuel cells at laboratory scale.

When will we see the results of your research on the road or on rails?

Marion Merklein: If we want to make noticeable progress with the use of hydrogen in the mobility sector, we need a level of technology that corresponds to that of the internal combustion engine. We are at least 10 years away from achieving this. But we are working on closing the gap.

by Matthias Münch

This article is part of the FAU Magazin

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