Fuel Cells and Electrolyzers (FCE)

The Fuel Cells and Electrolysis group´s research is related to the electrochemical and microstructural characterization and modeling of fuel cells and electrolyzers. Our approach covers multiple scales from the porous electrode structure to the system level.

We analyze the physicochemical processes taking place in the cell and correlate them to material and microstructural features, cell and stack design as well as operating parameters. The focus is on cell, repeat unit and stack-testing, applying realistic operating conditions in specialized test benches or even testing in the system. Currently, the focus is on high-temperature solid oxide cells (SOC), operated in both solid oxide fuel cell (SOFC) and solid oxide electrolyzer cell (SOEC) modes, and on polymer electrolyte membrane fuel cells (PEMFC) for mobile applications.

For the evaluation of the processes taking place in the cells, stationary (IV-curves, long-term tests) and dynamic measurement methods (impedance spectroscopy, NFRA) are used. For further investigations operando gas analysis (µGC, MS), structural (XRD), microscopic (SEM, light and laser microscopy) and tomographic methods (FIB-REM, µCT) are available.

Modeling is performed on multiple scales - from spatially resolved 3D models of porous electrodes, homogenized 0 and 1D electrode and cell models, 2 and 3D FEM models for cells and stacks to models for fuel cell systems. In modeling, the focus is on experimentally based parameterization, impedance analysis via the distribution function of relaxation times and physicochemical equivalent circuits provide the model structure and the required model parameters to describe transport processes and electrochemical reactions in the cell. Validation as an essential part of modeling is performed via complementary measurements.

Simulations provide information about non-measurable state variables in the cell, stack or system, reveal the behavior of new electrode-, cell- and stack-designs and enable the virtual integration of new components into a system.

contact: Dr.-Ing. André Weber