Self-healing properties of Ce/Co-coated stainless steel under simulated intermediate temperature solid oxide fuel cell conditions
Journal article, 2021

The interconnects used in solid oxide fuel cells (SOFC) are usually shaped into a corrugated form that creates gas channels. Coatings are applied onto an interconnect to increase its longevity by reducing Cr(VI) evaporation and oxide scale growth. To date many manufacturers first deform the interconnect and then apply the coating. However, the reverse (hereinafter termed pre-coating) would be more cost-effective, because large-scale roll-to-roll coating processes could then be used instead of batch coating processes. The drawback of this method is that cracks are introduced into the coating during deformation. The present work shows that the cracks heal after relatively short exposure times for the often-used Ce/Co coating (10 nm Ce and 640 nm Co) even at low operating temperatures (650 °C and 750 °C). The Cr evaporation rate of pre-coated deformed Ce/Co-coated AISI 441, even though slightly elevated in the beginning of the exposure, decreases and stabilizes to rates that are comparable to that of undeformed Ce/Co-coated AISI 441. SEM micrographs show that the cracks introduced during the shaping of the interconnect heal after roughly 70 h of exposure at 750 °C and 360 h of exposure at 650 °C.

Interconnect

Cr-evaporation

Solid oxide fuel cell

Corrosion

Ce/Co coating

Self-healing

Author

Claudia Goebel

Chalmers, Chemistry and Chemical Engineering, Energy and Material, Environmental Inorganic Chemistry 1

Vijayshankar Asokan

Chalmers, Chemistry and Chemical Engineering, Energy and Material, Environmental Inorganic Chemistry 1

Sarah Khieu

Chalmers, Chemistry and Chemical Engineering, Energy and Material, Environmental Inorganic Chemistry 1

Jan-Erik Svensson

Chalmers, Chemistry and Chemical Engineering, Energy and Material, Environmental Inorganic Chemistry 1

Jan Froitzheim

Chalmers, Chemistry and Chemical Engineering, Energy and Material, Environmental Inorganic Chemistry 1

Surface and Coatings Technology

0257-8972 (ISSN)

Vol. 428 127894

Subject Categories

Manufacturing, Surface and Joining Technology

Other Chemical Engineering

Other Materials Engineering

DOI

10.1016/j.surfcoat.2021.127894

More information

Latest update

11/29/2021