Investigating Bubble Formation and Evolution in Vanadium Redox Flow Batteries via Synchrotron X-Ray Imaging

Duan K, Köble K, Ershov A, Schilling M, Rampf A, Cecilia A, Faragó T, Zuber M, Baumbach T, Sui Pc, Zeis R (2025)

Publication Type: Journal article

Publication year: 2025

Journal

Chemsuschem Wiley-VCH Verlag

DOI: 10.1002/cssc.202500282

Abstract

The parasitic hydrogen evolution reaction (HER) hinders electrolyte transport. It reduces the effective electrochemical surface area in the negative half-cell of vanadium redox flow batteries (VRFBs), resulting in substantial efficiency losses. This study investigates the formation and evolution of hydrogen bubbles within VRFB electrodes through comprehensive experimental characterization and a detailed analysis of the resolved bubbles. The electrode is imaged using synchrotron X-ray tomography, and gas bubbles in the images are identified and characterized using a deep learning model combined with a morphological analysis tool. The HER intensity increases at more negative working electrode potentials, causing residual bubbles to grow and fuse in the electrode central region. In contrast, independent bubbles predominantly form at the electrode edges. Furthermore, bubble growth leads to the gradual development of irregular shapes. These observations provide insights into bubble formation and evolution rules, contributing to a better understanding of the system.

Authors with CRIS profile

Roswitha Zeis

Involved external institutions

Helmholtz Institut Ulm DE Germany (DE) Karlsruhe Institute of Technology (KIT) DE Germany (DE) Wuhan University of Technology CN China (CN)

How to cite

APA:

Duan, K., Köble, K., Ershov, A., Schilling, M., Rampf, A., Cecilia, A.,... Zeis, R. (2025). Investigating Bubble Formation and Evolution in Vanadium Redox Flow Batteries via Synchrotron X-Ray Imaging. Chemsuschem. https://doi.org/10.1002/cssc.202500282

MLA:

Duan, Kangjun, et al. "Investigating Bubble Formation and Evolution in Vanadium Redox Flow Batteries via Synchrotron X-Ray Imaging." Chemsuschem (2025).

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