DFG Walter-Benjamin-Stipend granted for NMR research of L-ROMs

DFG funded research stay at the Institute of Science and Technology Austria (ISTA) in Stefan Freunberger’s group for the NMR research of liquid organic redox-active materials (L-ROMs)

The Deutsche Forschungsgemeinschaft (DFG) granted a three-month research stay for Sven Jovanovic as part of the Walter-Benjamin program. The research will be conducted in the group of Stefan Freunberger at the Institute of Science and Technology Austria (ISTA) in Klosterneuburg. The project aims to characterize and study liquid redox-active materials (L-ROMs) by means of PFG diffusion and exchange NMR experiments. L-ROMs in combination with an electrolyte salt and some diluent can be applied in liquid-flow-batteries, where they act simultaneously as electrochemically active material as well as the electrolyte solvent. However, the properties (e.g. viscosity and conductivity) of L-ROMs change significantly as a function of state-of-charge and electrolyte salt concentration. In addition, exchange reactions between the neutral L-ROMs and their oxidized/reduced counterparts occur. All these factors impact the operation of a redox-flow battery. Thus, it is critical to fully characterize L-ROM mixtures at all relevant states and compositions. Here, NMR spectroscopy can provide information via pulsed field gradient (PFG) diffusion experiments and exchange spectroscopy (EXSY). PFG NMR assesses the diffusion of the electrolyte and the L-ROMs, enabling the determination of viscosity, transfer coefficient, and conductivity. EXSY allows the qualitative and quantitative validation of the dynamic equilibration reactions between charged and uncharged L-ROMs.

In conclusion, this research project intends to establish NMR techniques as characterization tools for L-ROM materials and mixtures. In order to accomplish this goal, the NMR experiments have to be carefully adjusted to the special properties of L-ROMs. Finally, the results of the studies will attempt to support the construction of scalable, cost-effective, and non-toxic redox-flow batteries for various applications. 

Dr. Sven JovanovicPostdoc Spektroskopie AbteilungBuilding 10.3 / Room 412+49 2461/61-9718