Reduktion der Chromfreisetzung aus metallischen Interkonnektoren für Hochtemperaturbrennstoffzellen durch Schutzschichtsysteme

Planar Solid Oxid Fuel Cells (SOFC) show interesting advantages in their characteristics compared to other fuel cells and heat engines because of their high efficiency. Chromiumbased steels and chromium contending compounds are used as interconnect material for a temperature range between 600°C and 900°C. These materials cause degradation of cells in SOFC because of their volatile Cr-species. The amount of evaporated chromium depends on temperature and humidity. In this work the connection is shown over a wide range of water partial pressure. There are two possibilities to reduce Cr evaporation. On one hand lowering the temperature will lowering the Cr evaporation rate. On the other hand Cr evaporation can be lowered by protective coatings. In this work the temperature and coating material dependence of Cr evaporation is measured. For high temperatures of about 900°C the Ducrolloy material is used. For temperatures of 800°C the Crofer22APU, CroferH, IT11 and F17TNB are tested with different coatings. For temperatures of 600°C ferritic steel and also austenitic steel such as 1.4845 is tested. Coating material of Mn3O4 and MnCo1.9Fe0.1O4 as protective material and LCC10 and LCC13 as contact layer are selected. The reduction of Cr release in the case of Mn3O4 (10-11 kgm-2s-1) is one order of magnitude lower than in the case of an uncoated steel (10-10 kgm-2s-1). For the MnCo1.9Fe0.1O4 material a further reduction of Cr release of up to 10-12 kgm-2s-1 is possible. The Cr evaporation rate of a coated material is also influenced by the coating method. Wet powder sprayed coatings have a porous structure and a reactive layer during annealing. Plasma sprayed coatings show dense layers with the best Cr reduction so far.

Grantor dc:publisher

Publikationsserver der RWTH Aachen University

Year dc:date

2009

Author dc:creator

• Trebbels, René

Contributors dc:contributor

• Singheiser, Lorenz

• info:eu-repo/classification/ddc/620
• Festoxidbrennstoffzelle
• Interkonnektor
• Schutzschicht
• Ingenieurwissenschaften
• Chromverdampfung
• Transpirationsmethode
• Cr evaporation
• transpiration method

Statement dc:rights

• info:eu-repo/semantics/openAccess

Language dc:language

ger

Identifier

https://publications.rwth-aachen.de/search?p=id:%22RWTH-CONV-113504%22

OAI record oai:identifier

https://publications.rwth-aachen.de/oai2d?verb=GetRecord&metadataPrefix=oai_dc&identifier=oai%3Apublications.rwth-aachen.de%3A51192