Chromium vaporization from mechanically deformed pre-coated interconnects in Solid Oxide Fuel Cells
Artikel i vetenskaplig tidskrift, 2015

Cathode poisoning, associated with Cr evaporation from interconnect material, is one of the most important degradation mechanisms in Solid Oxide Fuel Cells when Cr 2 O 3 -forming steels are used as the interconnect material. Coating these steels with a thin Co layer has proven to decrease Cr vaporization. To reduce production costs, it is suggested that thin metallic PVD coatings be applied to each steel strip before pressing the material into interconnect shape. This process would enable high volume production without the need for an extra post-coating step. However, when the pre-coated material is mechanically deformed, cracks may form and lower the quality of the coating. In the present study, Chromium volatilization is measured in an air-3% H 2 O environment at 850 C for 336 h. Three materials coated with 600 nm Co are investigated and compared to an uncoated material. The effect of deformation is investigated on real interconnects. Microscopy observations reveal the presence of cracks in the order of several μm on the deformed pre-coated steel. However, upon exposure, the cracks can heal and form a continuous surface oxide rich in Co and Mn. As an effect of the rapid healing, no increase in Cr vaporization is measured for the pre-coated material.

Interconnect

Corrosion

Vaporization

Self-healing

Coating

SOFC

Författare

Hannes Falk Windisch

Chalmers, Kemi och kemiteknik, Energi och material, Oorganisk miljökemi

Mohammad Sattari

Chalmers, Kemi och kemiteknik, Energi och material, Oorganisk miljökemi

Jan-Erik Svensson

Chalmers, Kemi och kemiteknik, Energi och material, Oorganisk miljökemi

Jan Froitzheim

Chalmers, Kemi och kemiteknik, Energi och material, Oorganisk miljökemi

Journal of Power Sources

0378-7753 (ISSN)

Vol. 297 217-223 21526

Ämneskategorier

Oorganisk kemi

DOI

10.1016/j.jpowsour.2015.07.085

Mer information

Skapat

2017-10-07