Electrocatalytic Interface Engineering
The Electrocatalytic Interface Engineering (German: Elektrokatalytische Grenzflächenverfahrstechnik (EGV)) research unit concentrates on technical interfaces of electrocatalytic devices. Examples of such technical interfaces are the catalyst layers, membranes or transport layers as well as their interfaces in e.g. fuel cells or electrolysers. The central research question for the field of the research unit is: How to get the best possible structure for the functionality of a given interfacial layer or layer system?
To approach this question there are three important subtopics which can be approached by more specific research questions:
- What is the structure of a given electrocatalytic system? - Tomography
The first question is how to get a structure at all, which for a multi-phase, nanoporous or even hierarchically structured layer system in electrocatalytic devices can be a challenge per se. In the past, we developed methods for nanotomographic reconstruction of nanoporous electrode materials by focused ion beam / scanning electron micrcoscopy tomography (FIB-SEMt). This method is based on infiltrating the pore space by atomic layer deposition. Furthermore, we investigate methods on how to assess hierarchical materials systems by the use of multiple tomographic approaches (e.g. FIB-SEMt and X-ray tomography) at the same time.
- What is the structure-macroscopic property relationship in electrocatalytic systems? – Modeling
In this area we combine nano- and microtomographic imaging with transport parameter simulation. The idea here is that by assessing the real structrure of e.g. the electrodes in a fuel cell by tomography and successive pore-scale modeling, an understanding of e.g. mass transport limiting factors or structural degradation during aging can be gained. Successivley this knowledge can be exploited to improve the structure in a specific system.
- How to create the best suitable structure for an electrocatalytic system? – Additive Manufacturing
To improve structure, additive manufacturing techniques that provide a spatial control are used. The idea here is to implement the improved structures that were previously found by modeling or by more heuristic approaches. For this purpose, different deposition techniques, such as spray coating or inkjet techniques or electrospinning are applied. In conjunction, these methods can be applied to receive composite membranes or structured membrane-electrode assemblies.
Additionally, we perform full cell tests using the various test benches available in our research unit. Further, we perform different synthesis approaches, particularly for the creation of nanoparticles.
Electrocatalysis for fuel cells
- C. V. Pham, M. Klingele, B. Britton, K. R. Vuyyuru, T. Unmuessig, S. Holdcroft, A. Fischer, S. Tiele, Tridoped Reduced Graphene Oxide as a Metal‐Free Catalyst for Oxygen Reduction Reaction Demonstrated in Acidic and Alkaline Polymer Electrolyte Fuel Cells, 2017, Advanced Sustainable Systems
Manufacturing of fuel cells
- M. Breitwieser, C. Klose, A. Hartmann, A. Büchler, M. Klingele, S. Vierrath, R. Zengerle, S. Thiele, Cerium Oxide Decorated Polymer Nanofibers as Effective Membrane Reinforcement for Durable, High‐Performance Fuel Cells, 2017, Advanced Energy Materials
- M. Klingele, M. Breitwieser, R. Zengerle, S. Thiele, Direct deposition of proton exchange membranes enabling high performance hydrogen fuel cells, 2015, Journal of Materials Chemistry A
Imaging and virtual design of fuel cells, electrolysers and batteries
- P. Lettenmeier, S. Kolb, N. Sata, A. Fallisch, L. Zielke, S. Thiele, A. S. Gago, K. A. Friedrich, Comprehensive investigation of novel pore-graded gas diffusion layers for high-performance and cost-effective proton exchange membrane electrolyzers, 2017, Energy and Environmental Science
- S. Vierrath, F. Güder, A. Menzel, M. Hagner, R. Zengerle, M. Zacharias, S. Thiele, Enhancing the quality of the tomography of nanoporous materials for better understanding of polymer electrolyte fuel cell materials, 2015, Journal of Power Sources
- L. Zielke, T. Hutzenlaub, D. R. Wheeler, C. W. Chao, I. Manke, A. Hilger, N. Paust, R. Zengerle, S. Thiele, Three‐Phase Multiscale Modeling of a LiCoO2 Cathode: Combining the Advantages of FIB–SEM Imaging and X‐Ray Tomography, 2015, Advanced Energy Materials
- L. Zielke, T. Hutzenlaub, D. R. Wheeler, I. Manke, T. Arlt, N. Paust, R. Zengerle, S. Thiele, A Combination of X‐Ray Tomography and Carbon Binder Modeling: Reconstructing the Three Phases of LiCoO2 Li‐Ion Battery Cathodes, 2014, Advanced Energy Materials