Electrochemical Energy Systems | Junior Research Group

Dr. Severin Vierrath, Dr. Melanie Bühler, Dr. Carolin Klose

EES Gruppenbild 2023

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HiWi / Student assistant:
Hydrogen Permeation in Anion-Exchange Membrane (AEM) Water Electrolysis

04/2025

Alexander Kohushölter, M.Sc.
alexander.kohushoelter@imtek.uni-freiburg.de

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Competence

The junior research group “Electrochemical Energy Systems” develops novel fuel cells, batteries and electrolysers. Our focus is on innovative manufacturing methods and materials, as well as micro-characterization and 3D imaging processes for these technologies.

Manufacturing and characterization

We develop new manufacturing methods and alternative materials for electrochemical energy applications: fuel cells and electrolysis cells and redox flow batteries. With new membrane systems, we are increasing the power density and durability. Furthermore, we develop new electrode structures that enable higher power densities. Methods such as electrospinning, spray coating and scalable coating processes are available in the group for this purpose. We characterize new materials and manufacturing methods electrochemically in fuel cell, electrolysis and battery test stands, as well as ex-situ in our microanalysis laboratory (µXRF, Xe-Plasma FIB / SEM, Raman microscopy, …).

We cover the entire value chain from catalyst and membrane production, ink and MEA production as well as electrochemical and microscopic analysis.

Latest developments in the group

Increased electrolysis performance with a low catalyst content

Iridium oxide is a particularly rare and expensive catalyst material that has so far been indispensable for water electrolysis. Therefore, the reduction in iridium oxide loading is very important for the commercialization of hydrogen production via electrolysis. We have made significant advances in the manufacture of electrolysis membrane electrode assemblies:
By introducing iridium oxide nanofibers, the electrical transverse conductivity of the catalyst layers could be significantly improved leading to one of the highest efficiencies with low IrOx loading.
(https://pubs.acs.org/doi/abs/10.1021/acsaem.0c00735 )

The technology received the F-Cell Award in 2019 and a patent has been submitted. (https://f-cell.de/award/ )

Manufacture of fluorine-free fuel and electrolysis cells

Commercially available fuel and electrolysis cells today contain fluorine-based polymers, so-called perfluorinated sulfonic acids. With alternative materials based on polysulfones and polyphenylenes, we were able to take a major step towards fluorine-free cells with comparable performance:

https://onlinelibrary.wiley.com/doi/full/10.1002/aenm.201903995

Reconstruction of electrodes to simulate transport properties

With an infiltration method developed in our group via atomic layer deposition, we are able to produce reliable 3D reconstructions of the nanostructure of fuel cell, battery or electrolysis electrodes. With our extensive software equipment and expertise, we are able to assess the substance transport in these electrodes quantitatively. The methodology has now been transferred to fuel cells, electrolysis cells or Li-ion batteries.

Projects and sponsors

Current research projects

Fe-Based Metal-Organic Frameworks as Photocatalysts for Energy and Environmental Applications,
Alexander von Humboldt-Stiftung
Camelot, EU Horizon 2020
CO₂-to-X, Vector Stiftung
Plug-In, BMBF
FC-CAT, BMBF
NeutroSense, BMBF
AlkaCell, Vector-Stiftung
PSU-MEA-III, BMBF
FlexCoat, BMBF

Past projects

Dekade, BMBF
DirectMEA, Ministry of Economics Baden-Wurttemberg
Inspire, EU Horizon 2020
Neurofast, BMBF

Images of our non-profit projects

Image database. Please ask for the rights of use.

Team

Head

Scientific staff

Dr. habil. Klaus-Dieter Kreuer
Leonhard Probst

Dr. Giorgi Titvinidze
Frieder Junginger
Clara Schare
Hendrik Sannemüller
Dr. Dennis Rusitov
Tim Kiefer
Sophia Kilian
Miriam von Holst

PostDoc

Dr. Naghmeh Mirbagheri
Dr. Tym de Wild
Dr. Lukas Metzler
Dr. Andreas Münchinger
Dr. Joey Disch
Dr. Susanne Koch

PhD Candidate

Edgar Cruz Ortiz
Christian Piesold
Julian Stiegeler
Fiona Pescher
Hannes Liepold
Frederik Brendel
Alexander Kohushölter
Luis Hagner
Luca Bohn
Jacquline Goldmann
Josephine Häberlein

Master student, Bachelor student, Student assistant

Kushal Shah
Felix Vossbrink
Mika Stricker
Lasha Khusishvili
Theresa Groth
Liel Bühler
Bharat Sawant
Macarena Pizzaro
Xaver Kolb
Emilie Behringer
Rusudan Sulaberidze

Past member

Dr. Matthias Breitwieser
Arne Götze
Zsoltan Danilo
Dr. Lukas Zielke
Armin Hartmann
Kevin Holdcroft
Michaela Frase

Dr. Lili Liu
Dr. Matthias Klingele
Peter Holzapfel
Dr. Witali Beichel
Dr. Friedemann Hegge
Dr. Van Chuyen Pham
Riko Moroni
Mohammad Solihul Mumin
Philipp Veh
Brian Shanahan
Dr. Florian Lombeck
Claudia Schwarz
Dr. Andreas Büchler
Farmal Khan
Dilara Sultanova
Neda Khalili Sabet
Jacqueline Goldmann
Akshaya Mani
Mohamed Dhia Chabaane
Hien Nguyen
Koray Yildirim
Miriam von Holst
Leonhard Probst
Niklas van Treel
Mohamed El Shamy
Dr. Philipp Heizmann
Dr. Marco Viviani
Hassan Fadlullah
Hannes Grammel
Philippe Geideck

Latest Publications

Electrolysis

Hegge, F., Lombeck, F., Cruz Ortiz, E., Bohn, L., von Holst, M., Kroschel, M., ... & Vierrath, S. (2020). Efficient and Stable Low Iridium Loaded Anodes for PEM Water Electrolysis Made Possible by Nanofiber Interlayers. ACS Applied Energy Materials, 3(9), 8276-8284.
Ortiz, E. C., Hegge, F., Breitwieser, M., & Vierrath, S. (2020). Improving the performance of proton exchange membrane water electrolyzers with low Ir-loaded anodes by adding PEDOT: PSS as electrically conductive binder. RSC Advances, 10(62), 37923-37927.
Klose, C., Saatkamp, T., Münchinger, A., Bohn, L., Titvinidze, G., Breitwieser, M., ... & Vierrath, S. (2020). All‐Hydrocarbon MEA for PEM Water Electrolysis Combining Low Hydrogen Crossover and High Efficiency. Advanced Energy Materials, 10(14), 1903995.

Fuel Cells

Veh, P., Britton, B., Holdcroft, S., Zengerle, R., Vierrath, S., & Breitwieser, M. (2020). Improving the water management in anion-exchange membrane fuel cells via ultra-thin, directly deposited solid polymer electrolyte. RSC Advances, 10(15), 8645-8652.

Redox-Flow Batteries

Shanahan, B., Böhm, T., Britton, B., Holdcroft, S., Zengerle, R., Vierrath, S., ... & Breitwieser, M. (2019). 30 μm thin hexamethyl-p-terphenyl poly (benzimidazolium) anion exchange membrane for vanadium redox flow batteries. Electrochemistry Communications, 102, 37-40.

Micro Analysis

Mu’min, M. S., Böhm, T., Moroni, R., Zengerle, R., Thiele, S., Vierrath, S., & Breitwieser, M. (2019). Local hydration in ionomer composite membranes determined with confocal Raman microscopy. Journal of Membrane Science, 585, 126-135.
Böhm, T., Moroni, R., Breitwieser, M., Thiele, S., & Vierrath, S. (2019). Spatially resolved quantification of ionomer degradation in fuel cells by confocal Raman microscopy. Journal of The Electrochemical Society, 166(7), F3044.
Hegge, F., Moroni, R., Trinke, P., Bensmann, B., Hanke-Rauschenbach, R., Thiele, S., & Vierrath, S. (2018). Three-dimensional microstructure analysis of a polymer electrolyte membrane water electrolyzer anode. Journal of Power Sources, 393, 62-66.

Awards

f-cell award – Innovationspreis Brennstoffzelle in der Kategorie Forschung & Entwicklung (09/2019)
Innovationspreis für Masterarbeit (05/2019)
Nachwuchsförderpreis der Eva-Mayr-Stihl-Stiftung (11/2018)
Innovationspreis des Deutschen Wasserstoff- und Brennstoffzellenverbands (DWV) (04/2018)
Best Poster Prize beim Hereaus-Seminar, Bad Honnef (07/2017)
Best-Poster-Award für Brennstoffzellenkonzept (02/2017)
Promotionspreis für Matthias Breitwieser (11/2015)
Prämierter Vortrag und Top-Platzierung beim Fotowettbewerb der Baden-Württemberg Stiftung (10/2015)
f-cell award – Innovationspreis Brennstoffzelle (10/2015)