Model-based prediction of the ohmic resistance of metallic interconnects from oxide scale growth based on scanning electron microscopy

Linder, Markus; Hocker, Thomas; Holzer, Lorenz; Friedrich, K. Andreas; Iwanschitz, Boris; Mai, Andreas; Schuler, J. Andreas

doi:10.1016/j.jpowsour.2014.08.098

Publication type:	Article in scientific journal
Type of review:	Peer review (publication)
Title:	Model-based prediction of the ohmic resistance of metallic interconnects from oxide scale growth based on scanning electron microscopy
Authors:	Linder, Markus Hocker, Thomas Holzer, Lorenz Friedrich, K. Andreas Iwanschitz, Boris Mai, Andreas Schuler, J. Andreas
DOI:	10.1016/j.jpowsour.2014.08.098
Published in:	Journal of Power Sources
Volume(Issue):	272
Page(s):	595
Pages to:	605
Issue Date:	2014
Publisher / Ed. Institution:	Elsevier
ISSN:	0378-7753 1873-2755
Language:	English
Subjects:	Scale growth rate law; Interconnect; Map; Solid oxide fuel cell (SOFC)
Subject (DDC):	530: Physics 621.3: Electrical, communications, control engineering
Abstract:	The increase of ohmic losses caused by continuously growing Cr2O3 scales on metallic interconnects (MICs) is a major contribution to the degradation of SOFC stacks. Comparison of measured ohmic resistances of chromium- (CFY) and ferritic-based alloy (Crofer) MICs at 850°C in air with the growth of mean oxide scale thicknesses, obtained from SEM cross section images, reveals a non-trivial, non-linear relationship. To understand the correlation between scale evolution and resulting ohmic losses, 2D finite element (FE) simulations of electrical current distributions have been performed for a large number of real oxide scale morphologies. It turns out that typical morphologies favor nonhomogeneous electrical current distributions, where the main current flows over rather few “bridges”, i.e. local spots with relatively thin oxide scales. These current-“bridges” are the main reason for the non-linear dependence of ohmic losses on the corresponding oxide scale morphology. Combining electrical conductivity and SEM measurements with FE simulations revealed two further advantages: it permits a more reliable extrapolation of MIC-degradation data over the whole stack lifetime and it provides a method to assess the effective electrical conductivity of thermally grown Cr2O3 scales under stack operation.
URI:	https://digitalcollection.zhaw.ch/handle/11475/1635
Fulltext version:	Published version
License (according to publishing contract):	Licence according to publishing contract
Departement:	School of Engineering
Organisational Unit:	Institute of Computational Physics (ICP)
Appears in collections:	Publikationen School of Engineering

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Linder, M., Hocker, T., Holzer, L., Friedrich, K. A., Iwanschitz, B., Mai, A., & Schuler, J. A. (2014). Model-based prediction of the ohmic resistance of metallic interconnects from oxide scale growth based on scanning electron microscopy. Journal of Power Sources, 272, 595–605. https://doi.org/10.1016/j.jpowsour.2014.08.098

Linder, M. et al. (2014) ‘Model-based prediction of the ohmic resistance of metallic interconnects from oxide scale growth based on scanning electron microscopy’, Journal of Power Sources, 272, pp. 595–605. Available at: https://doi.org/10.1016/j.jpowsour.2014.08.098.

M. Linder et al., “Model-based prediction of the ohmic resistance of metallic interconnects from oxide scale growth based on scanning electron microscopy,” Journal of Power Sources, vol. 272, pp. 595–605, 2014, doi: 10.1016/j.jpowsour.2014.08.098.

LINDER, Markus, Thomas HOCKER, Lorenz HOLZER, K. Andreas FRIEDRICH, Boris IWANSCHITZ, Andreas MAI und J. Andreas SCHULER, 2014. Model-based prediction of the ohmic resistance of metallic interconnects from oxide scale growth based on scanning electron microscopy. Journal of Power Sources. 2014. Bd. 272, S. 595–605. DOI 10.1016/j.jpowsour.2014.08.098

Linder, Markus, Thomas Hocker, Lorenz Holzer, K. Andreas Friedrich, Boris Iwanschitz, Andreas Mai, and J. Andreas Schuler. 2014. “Model-Based Prediction of the Ohmic Resistance of Metallic Interconnects from Oxide Scale Growth Based on Scanning Electron Microscopy.” Journal of Power Sources 272: 595–605. https://doi.org/10.1016/j.jpowsour.2014.08.098.

Linder, Markus, et al. “Model-Based Prediction of the Ohmic Resistance of Metallic Interconnects from Oxide Scale Growth Based on Scanning Electron Microscopy.” Journal of Power Sources, vol. 272, 2014, pp. 595–605, https://doi.org/10.1016/j.jpowsour.2014.08.098.