The influence of constrictivity on the effective transport properties of porous layers in electrolysis and fuel cells

Holzer, Lorenz; Wiedenmann, Daniel; Münch, Beat; Keller, Lukas; Prestat, Michel; Gasser, Philippe; Robertson, Iain; Grobéty, Bernard

doi:10.21256/zhaw-1568

Please use this identifier to cite or link to this item: https://doi.org/10.21256/zhaw-1568

Publication type:	Article in scientific journal
Type of review:	Peer review (publication)
Title:	The influence of constrictivity on the effective transport properties of porous layers in electrolysis and fuel cells
Authors:	Holzer, Lorenz Wiedenmann, Daniel Münch, Beat Keller, Lukas Prestat, Michel Gasser, Philippe Robertson, Iain Grobéty, Bernard
DOI:	10.21256/zhaw-1568 10.1007/s10853-012-6968-z
Published in:	Journal of Materials Science
Volume(Issue):	48
Issue:	7
Page(s):	2934
Pages to:	2952
Issue Date:	2013
Publisher / Ed. Institution:	Springer
ISSN:	0022-2461
Language:	English
Subjects:	Map
Subject (DDC):	621.3: Electrical, communications, control engineering
Abstract:	The aim of the present investigation is to define microstructure parameters, which control the effective transport properties in porous materials for energy technology. Recent improvements in 3D-imaging (FIB-nanotomography, synchrotron X-ray tomography) and image analysis (skeletonization and graph analysis, transport simulations) open new possibilities for the study of microstructure effects. In this study, we describe novel procedures for a quantitative analysis of constrictivity, which characterizes the so-called bottleneck effect. In a first experimental part, methodological tests are performed using a porous (La,Sr)CoO3 material (SOFC cathode). The tests indicate that the proposed procedure for quantitative analysis of constrictivity gives reproducible results even for samples with inhomogeneous microstructures (cracks, gradient of porosity). In the second part, 3D analyses are combined with measurements of ionic conductivity by impedance spectroscopy. The investigations are preformed on membranes of electrolysis cells with porosities between 0.27 and 0.8. Surprisingly, the tortuosities remain nearly constant (1.6) for the entire range of porosity. In contrast, the constrictivities vary strongly and correlate well with the measured transport resistances. Hence, constrictivity represents the dominant microstructure parameter, which controls the effective transport properties in the analysed membrane materials. An empirical relationship is then derived for the calculation of effective transport properties based on phase volume fraction, tortuosity, and constrictivity.
URI:	https://digitalcollection.zhaw.ch/handle/11475/2124
Fulltext version:	Published version
License (according to publishing contract):	Licence according to publishing contract
Restricted until:	2019-01-01
Departement:	School of Engineering
Organisational Unit:	Institute of Computational Physics (ICP)
Appears in collections:	Publikationen School of Engineering

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Holzer, L., Wiedenmann, D., Münch, B., Keller, L., Prestat, M., Gasser, P., Robertson, I., & Grobéty, B. (2013). The influence of constrictivity on the effective transport properties of porous layers in electrolysis and fuel cells. Journal of Materials Science, 48(7), 2934–2952. https://doi.org/10.21256/zhaw-1568

Holzer, L. et al. (2013) ‘The influence of constrictivity on the effective transport properties of porous layers in electrolysis and fuel cells’, Journal of Materials Science, 48(7), pp. 2934–2952. Available at: https://doi.org/10.21256/zhaw-1568.

L. Holzer et al., “The influence of constrictivity on the effective transport properties of porous layers in electrolysis and fuel cells,” Journal of Materials Science, vol. 48, no. 7, pp. 2934–2952, 2013, doi: 10.21256/zhaw-1568.

HOLZER, Lorenz, Daniel WIEDENMANN, Beat MÜNCH, Lukas KELLER, Michel PRESTAT, Philippe GASSER, Iain ROBERTSON und Bernard GROBÉTY, 2013. The influence of constrictivity on the effective transport properties of porous layers in electrolysis and fuel cells. Journal of Materials Science. 2013. Bd. 48, Nr. 7, S. 2934–2952. DOI 10.21256/zhaw-1568

Holzer, Lorenz, Daniel Wiedenmann, Beat Münch, Lukas Keller, Michel Prestat, Philippe Gasser, Iain Robertson, and Bernard Grobéty. 2013. “The Influence of Constrictivity on the Effective Transport Properties of Porous Layers in Electrolysis and Fuel Cells.” Journal of Materials Science 48 (7): 2934–52. https://doi.org/10.21256/zhaw-1568.

Holzer, Lorenz, et al. “The Influence of Constrictivity on the Effective Transport Properties of Porous Layers in Electrolysis and Fuel Cells.” Journal of Materials Science, vol. 48, no. 7, 2013, pp. 2934–52, https://doi.org/10.21256/zhaw-1568.