TY - JOUR
T1 - Method to Measure Area Specific Resistance and Chromium Migration Simultaneously from Solid Oxide Fuel Cell Interconnect Materials
AU - Tallgren, J.
AU - Himanen, O.
AU - Bianco, M.
AU - Mikkola, J.
AU - Thomann, O.
AU - Rautanen, M.
AU - Kiviaho, J.
AU - Van herle, J.
N1 - Project 51135
PY - 2019
Y1 - 2019
N2 - Chromium evaporation is identified as a major degradation mechanism in solid oxide fuel cell (SOFC) stacks. The major chromium source is the commonly used stainless steel interconnects, thus raising a need for protective coatings on the interconnect steel. Ex situ characterization methods of protective coatings involve chromium evaporation measurements, area specific resistance (ASR) measurements and long-term exposure tests. To replicate stack conditions, commonly used ASR measurement setups should be further developed. This work presents an improved characterization method for steels and coatings and aims to be an extension to state-of-the-art characterization methods. The studied steel samples, bare or coated, are placed adjacent to palladium foils with a screen-printed lanthanum-strontium-cobalt (LSC) layer and the resistivity over the pair is measured. The method offers similar contact materials, chromium migration mechanisms, electrical contacts and chemical interactions, as seen in stacks. Further, it enables post-test chromium migration analysis with electron microscopy. Demonstration of the method validated that protective coatings hindered both oxidation and chromium migration from the substrate steels. The presented method could aid in accelerating protective coating development.
AB - Chromium evaporation is identified as a major degradation mechanism in solid oxide fuel cell (SOFC) stacks. The major chromium source is the commonly used stainless steel interconnects, thus raising a need for protective coatings on the interconnect steel. Ex situ characterization methods of protective coatings involve chromium evaporation measurements, area specific resistance (ASR) measurements and long-term exposure tests. To replicate stack conditions, commonly used ASR measurement setups should be further developed. This work presents an improved characterization method for steels and coatings and aims to be an extension to state-of-the-art characterization methods. The studied steel samples, bare or coated, are placed adjacent to palladium foils with a screen-printed lanthanum-strontium-cobalt (LSC) layer and the resistivity over the pair is measured. The method offers similar contact materials, chromium migration mechanisms, electrical contacts and chemical interactions, as seen in stacks. Further, it enables post-test chromium migration analysis with electron microscopy. Demonstration of the method validated that protective coatings hindered both oxidation and chromium migration from the substrate steels. The presented method could aid in accelerating protective coating development.
KW - Chromium Poisoning
KW - Ferritic Stainless Steel
KW - Fuel Cells
KW - Planar SOFC Stack
KW - Protective Coating Development
KW - Stack Degradation
UR - http://www.scopus.com/inward/record.url?scp=85068694868&partnerID=8YFLogxK
U2 - 10.1002/fuce.201800169
DO - 10.1002/fuce.201800169
M3 - Article
AN - SCOPUS:85068694868
VL - 19
SP - 570
EP - 577
JO - Fuel Cells
JF - Fuel Cells
SN - 1615-6846
IS - 5
ER -