Membranes and Electrochemical Cells

Our synthetic strategy is based on the preparation and functionalization of polymer films via radiation-induced grafting to obtain membranes containing ionic sites. Activation of the base polymer film can be done using an electron beam (performed externally). For surface grafting, the film is activated in a plasma chamber. Activated films are stored in a fridge at a temperature of -80°C. For the grafting reaction, a wide range of vinyl monomers amenable to radical polymerization can be used, such as styrenes and acrylics.

The laboratory has a wide range of characterization methods for ex situ characterization of starting materials, intermediates and membranes: infrared and Raman spectroscopy for composition analysis, SEM-EDX, XPS, DSC/TGA, tensile testing machine, etc. The conductivity of membranes is measured using ac impedance spectroscopy (in-plane or through-plane). In addition, we have a well-equiped fuel cell test infrastructure with test benches for single cells up to stacks for 30 kW power output.

Water electrolysis plays a key role in future energy scenarios (power-to-gas). We study materials aspects of polymer electrolyte water electrolyzers with a few to increasing performance and efficiency and investigate mechanican and chemical aging phenomena of key cell components. Two custom-built test benches for cells of 25 cm2 active area can be operated up to a pressure of 20 bar. We can measure impedance spectra and monitor the purity of gases (in particular H₂ contamination in O₂) continuously.