Evaluation of Fe-Cr Alloys as Interconnects for Reduced Operation Temperature SOFCs

The stability of Fe-Cr alloys was investigated in atmosphere at 1073 K for solid oxide fuel cell (SOFC) interconnects. Oxide scale layers formed at the surface of Fe-Cr alloys changed the surface morphology of the alloy. The phases identified by X-ray diffraction were spinel oxides and at the surface. The diffusion profiles of several major and minor elements were measured by secondary ion mass spectrometry in its depth profile mode. The distribution of cations was in the following order from the free surface: Mn-, Fe-, La-rich inner oxides and alloy. The growth rate of the scale layer was determined from the thickness of the scale with a parabolic growth relationship: © 2003 The Electrochemical Society. All rights reserved.