Brainfood @ Noon: Die JCF Lunchtalks

 

Der wissenschaftliche Austausch ist ein zentrales Anliegen des JCF. Mit unseren neuen JCF-Lunchtalks schaffen wir ab Oktober 2025 eine virtuelle Plattform für junge Wissenschaftlerinnen und Wissenschaftler, um aktuelle Forschungsergebnisse kompakt zu präsentieren und sich disziplinübergreifend zu vernetzen.

An jedem ersten Freitag im Monat von 12:00 bis 13:00 Uhr laden das JCF und ausgewählte GDCh-Fachgruppen zu thematisch fokussierten Kurzvorträgen ein. Im Anschluss bleibt Raum für Diskussion und Austausch – ideal, um neue Perspektiven zu gewinnen und Kontakte innerhalb der Fachcommunity zu knüpfen.

Die ersten Termine im Überblick:

  • 10. Oktober 2025 – Elektrochemie & Batterieforschung
  • 07. November 2025 – Makromolekulare Chemie
  • 05. Dezember 2025 – Physikalische Chemie
  • 09. Januar 2026 – Biochemie
  • 06. Februar 2026 – Organische Chemie

Weitere Themen und Termine folgen.

Du promovierst selbst in einem der genannten Fachgebiete und möchtest deine Forschung in einem zehnminütigen Vortrag vorstellen? Dann freuen wir uns über deine Anmeldung!

Zur Anmeldung als Speaker*in: https://forms.gle/pajNcEuZuRnHqhZ66

 

Folgt uns auf Instagram: @jcf_lunchtalks

 

Unsere erste Session am 10. Oktober 2025 um 12:00 Uhr

In unserer ersten Lunchtalk-Session widmen wir uns der Elektrochemie und der Batterieforschung. Folgende Speakerinnen geben uns einen Einblick in ihre hochaktuelle Forschung:

 

Franziska Kühling, Carl von Ossietzky Universität Oldenburg

"New Insights on the Fundamentals of Bipolar Electrochemistry"

In bipolar electrochemistry, oxidation and reduction occur on the same electrode body, the so-called bipolar electrode, which is not physically connected to a power supply. The reactions at the bipolar electrode are induced by a voltage drop in the solution, which is caused by applying a voltage between two feeder electrodes.[1] In an open set-up, an ionic current, the so-called bypass current, flows through the electrolyte solution in parallel to the electronic current within the bipolar electrode. In a closed setup, the entire current passes through the bipolar electrode.[1] While bipolar electrodes are common in fuel cells[2], other stacked electrochemical reactors[3] or in fluidized bed reactors,[4] they have occasionally been used in material science and in electroanalysis, where the wireless nature is attractive for the integration of micrometer and nanometer sized electrodes.[1] So far, the complexity of the setup and the resulting potential distributions make it challenging to precisely control the potential of the bipolar electrode. This contribution explores cell conditions that allow wireless electrochemistry with potential control on one side of the bipolar electrode, which is usually necessary for electroanalytical applications. In this work, a closed bipolar setup was used with two interconnected microelectrodes as bipolar electrode. This particular setup has been extensively used by Zhang and coworkers to investigate the fundamentals of bipolar electrochemistry.[5–7] We investigated the influence of the size of the feeder electrodes and reactions at them on voltammetric experiments. Moreover, the potential of one side of the bipolar electrode was set by a redox couple in one half-cell of the closed setup. The influence of a varying bipolar efficiency on the capacitive current and on the required voltage between the feeder electrodes was also investigated. The bipolar efficiency is the ratio between the current through the bipolar electrode and the current between the feeder electrodes. Compared to previous reports,[8] in which the bipolar efficiency was changed by varying the diameter of the bipolar electrode, the bipolar efficiency was changed in this work by systematically varying the bypass current. This has the advantage that the influence of a changing interface between the bipolar electrode and the solution is avoided. We are currently investigating the time constant of bipolar setups in comparison to conventional three-electrode setups by chronoamperometry and electrochemical impedance spectroscopy. The accelerated responsiveness of bipolar electrochemical setups in their closed configuration could be promising for investigations of current transient of short time scales.

References

[1] L. Bouffier, N. Sojic, A. Kuhn in Electroanalytical Chemistry: A Series of Advances: Volume 27 (Eds.: A. J. Bard, C. G. Zoski), CRC Press, Boca Raton, FL, 2017.

[2] A. Hermann, T. Chaudhuri, P. Spagnol, Int. J. Hydrogen Energy 2005, 30, 1297.

[3] C. Comninellis, E. Plattner, P. Bolomey, J. Appl. Electrochem. 1991, 21, 415.

[4] J. R. Backhurst, J. M. Coulson, F. Goodridge, R. E. Plimley, M. Fleischmann, J. Electrochem. Soc. 1969, 116, 1600.

[5] S. M. Oja, B. Zhang, ChemElectroChem 2016, 3, 457.

[6] J. T. Cox, J. P. Guerrette, B. Zhang, Anal. Chem. 2012, 84, 8797.

[7] J. P. Guerrette, S. M. Oja, B. Zhang, Anal. Chem. 2012, 84, 1609.

[8] G. Loget, A. Kuhn in Electrochemistry: Volume 11: Nanosystems Electrochemistry (Eds.: R. G. Compton, J. D. Wadhawan), RSC Publishing, London, 2012.

 

Alena Neudert, Universität Bayreuth

"Hybrid all-Fe Redox Flow Battery: Coupling Theory and Experiment"

 The increasing need for renewable energy resources requires inexpensive and durable solutions for large-scale energy storage. Redox-flow batteries (RFB) are promising for such applications, as the positive and negative electroactive species are stored in tanks external to the cell stack and thus, power and energy can be scaled independently. While the vanadium and zinc-bromine RFBs are already commercially available, the hybrid all-iron RFB offers a more cost-effective, non-toxic and sustainable alternative. However, during charging, inhomogeneous iron deposition takes place on the negative electrode and simultaneously the parasitic hydrogen evolution reaction (HER) is favoured at negative potentials, which reduces the battery’s charging efficiency.

In a collaborative research project, the processes in the negative half-cell, namely iron plating and stripping and HER, are investigated by coupling kinetic Monte Carlo simulations and electrochemical experiments. The latter take place in an H-cell setup and on custom-made planar glassy carbon electrodes to follow the processes at different potentials, temperatures and pH-values. The results confirmed that elevated temperatures shift the onset potential of the reduction to less negative values, suggesting a lower overpotential for the plating reaction. Moreover, at higher temperatures, the peak area of iron oxidation increases compared to the reduction areas, respectively, showing an improvement of coulombic efficiency. Implementation of the results into the theoretical model, enables to predict the influence of different parameters (e.g. temperature, pH) in the future.