Boehm T, Moroni R, Breitwieser M, Thiele S, Vierrath S (2019)
Publication Type: Journal article
Publication year: 2019
Book Volume: 166
Pages Range: F3044-F3051
Journal Issue: 7
DOI: 10.1149/2.0051907jes
Ionomer membranes are crucial components ofmany electrochemical devices. In this work, confocal Ramanmicroscopy is employed to characterize Nafion ionomers quantitatively in pristine status and after usage as a proton exchange membrane in a fuel cell. Confocal Raman microscopy allows non-destructive thickness and equivalent weight measurements of Nafion with a 95% confidence interval of +/- 13 g mol(-1) at an equivalent weight of 1000 g mol(-1), which is significantly more accurate than previously reported methods. Characterization can be performed at a spatial resolution better than 2 mu m, providing insights into local membrane degradation after fuel cell operation. Membrane thinning to less than 40% of the initial thickness of Nafion NR-211 occurs after a 100 h open circuit voltage hold, accompanied by an anisotropic increase of the equivalent weight from 1035 g mol(-1) to an average of 1200 g mol(-1). Most pronounced increases are found close to the anode. Further, the characterization of a Nafion XL membrane shows that its microporous reinforcement is represented as increased equivalent weight with local heterogeneities within the membrane. These results show that confocal Raman microscopy is a valuable tool to investigate ionomers that are used as ion exchange membranes in electrochemical devices. (c) The Author(s) 2019. Published by ECS.
APA:
Boehm, T., Moroni, R., Breitwieser, M., Thiele, S., & Vierrath, S. (2019). Spatially Resolved Quantification of Ionomer Degradation in Fuel Cells by Confocal Raman Microscopy. Journal of The Electrochemical Society, 166(7), F3044-F3051. https://doi.org/10.1149/2.0051907jes
MLA:
Boehm, Thomas, et al. "Spatially Resolved Quantification of Ionomer Degradation in Fuel Cells by Confocal Raman Microscopy." Journal of The Electrochemical Society 166.7 (2019): F3044-F3051.
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