Bifunctional Catalysts

An efficient microtubular vanadium air redox flow battery (VARFB) relies heavily on high performance catalysts and tailor-made catalyst carriers. The DWI Aachen plays a leading role in the development of bifunctional catalysts and innovative membrane electrode assemblies within the BMBF lighthouse project tubulAir±.

DWI Aachen will cover the development of bifunctional catalysts for the application in microtubular VARFBs. The efficiency of state-of-the-art bifunctional catalysts can be increased with the addition of transition metals to the binary systems with the beneficial effect of a cost reduction. Aspects that influence the suitability of the catalyst are (a) the efficiency of reduction and oxidation of oxygen, (b) the long-term stability in operation, (c) cost and (d) the requirements concerning the application technology. In addition to the ternary bifunctional catalysts, suitable application technologies need to be developed.

An additional focus of DWI Aachen is the development of tailor-made tubular membrane electrode assemblies for the VARFB. High porosities for a high specific surface area and an architecture that reduces pore-blocking by water inclusion are crucial for the performance of the microtubular VARFB. The aim is to synthesize new tubular membrane electrode assemblies based on hollow fiber membrane spinning technology.