We are investigating property of Fe-Cr-Al alloy for the application of metal supported solid oxide fuel cell. In general, Fe-Cr-Al alloy showed high oxidation resistance because of its alumina-based oxide layer formed on the surface as a protective layer. We reported previously that the electrical conductivity of the surface oxide layer can be increased by a heat-treatment after coating of La_0.6Sr_0.4Co_0.2Fe_0.8O₃ (LSCF), La_0.8Sr_0.2MnO₃ (LSM), LaNi_0.6Fe_0.4O₃ (LNF), or Pr_0.8Sr_0.2MnO₃ (PrSM). The surface oxide layer on the Fe-Cr-Al alloy after the treatment changed to a microstructure consisting of γ-Al₂O₃ columns growing outward in the same direction, containing small amounts of elements such as Sr, Fe, La, Ni and Pr. The enhanced electrical conductivity may have resulted from the arrangement of the columnar structure, along with the electronic conduction path generated by the reaction of γ-Al₂O₃with these elements. Development status of a Fe-Cr-Al based metal supported cell will also be presented.

Acknowledgements

This research is supported by The Japan Science and Technology Agency (JST) through its “Center of Innovation Science and Technology based Radical Innovation and Entrepreneurship Program (COI Program)."