Redox flox batteries
Redox flow batteries store electrical energy chemically in the form of electrolyte solutions stored in tanks. The main advantage over other storage systems is that the storage capacity can be influenced by the volume of the electrolyte alone, regardless of the cell size. In our projects we want to better understand the aging of porous carbon electrodes and produce improved C-C composite electrodes. In particular, we also use electroanalytical methods (RDE, ACCV, DRT-EIS) to investigate the relationship between structure and activity.
The use of fuel cells as energy converters with high thermodynamic efficiency offers a climate-friendly and low-emission alternative to fossil fuels. Thus, the fuel cell is at the centre of the current hydrogen strategy of the Federal Government. Our research focuses on the synthesis of precious metal-based and non-precious metal-based nanostructured catalyst materials for electrochemical oxygen reduction. We are particularly interested in the so-called HT-PEM fuel cell, which, among other things, has the advantage of a higher operating temperature. We investigate the poisoning of the active Pt centers in operation with X-ray absorption spectroscopy and try to influence this positively by using organic additives.
Direct reductive conversion of CO2
For the chemical-material storage of renewable electricity, water electrolysis is to be directly coupled with the conversion of carbon dioxide (CO2) into higher-value products (e.g. CO, C2H4, CH3OH). Copper in particular is suitable as a catalyst for CO2 electrochemical reduction. In a current project we use Cu and CuAg films produced by negative hydrogen bubble tempering as model systems to analyze the influence of composition and pore size on the resulting products.
The electrospinning process is a method that can be varied in many ways to produce fibre structures with very high specific surfaces. Electrospun PAN felts can be carbonized and used in fuel cells, redox flow cells or in other electrochemical energy applications where highly porous materials are used. In our group we use electrospinning to produce fine-fibrous carbon networks and hollow fiber structures and investigate the combination of polymer fibers with metals.