MEET PhD Student Karin Sowa Wins Poster Prize

Excellent Research on Redox Flow Batteries

For her poster “Oxo-verdazyls for Organic Symmetric Redox Flow Batteries” Karin Sowa, PhD student at MEET Battery Research Center at the University of Münster and the International Graduate School BACCARA, was awarded at this year's International Flow Battery Forum in Vienna. Sowa impressed the jury with her previous poster pitch and received the award for the “Best Poster Discussion”. Linus Altemöller from the International Graduate School BACCARA won another poster prize. More than 350 participants attended the conference to discover the latest developments in the field of flow batteries.

New, Stable Radical Investigated

Redox flow batteries operate with two electrolyte compartments that contain the redox active material. These are separated by a membrane, which also enables ion exchange. As the performance and capacity of the batteries can be scaled up independently of each other and the size of the compartments is variable, the technology is particularly interesting for stationary energy storage.

Sowas research cooperation project with Elena Horst (University of Münster) focuses on redox flow batteries with a symmetric setup. Both compartments use the same organic radical molecule as active material. This has the advantage that only one material needs to be produced, the battery can be reversed, and no irreversible capacity loss occurs when material passes through the membrane. During the charging process of redox-flow batteries, the stable radicals can reversibly accept or donate an electron and can therefore be used as both cathode and anode. In her poster on N,N'-dialkylated oxo-verdazyl radicals, the researcher presented an important step in analyzing the degradation of these air-stable radicals. "We investigated the decomposition products of this radical after cyclic aging in a cell," explains Sowa. Based on these results, the research team was able to develop a molecular engineering approach that makes degradation during the charge and discharge processes in the battery more difficult. "These analyses have helped us to further improve the performance of the new, stable radical," Sowa summarizes.

Co-authors of the poster are Elena S. Horst and Prof. Dr Armido Studer, Organic Chemistry Institute of the University of Münster, Nick Fehlings, MEET Battery Research Center, Dr Mariano Grünebaum, Helmholtz Institute Münster of Forschungszentrum Jülich, as well as Prof. Dr Martin Winter, MEET Battery Research Center and Helmholtz Institute Münster.