Densification of Ce0.9Gd0.1O2-δ interlayer to improve the stability of La0.6Sr0.4 CO0.2Fe0.8O3-δ/Ce0.9Gd0.1O2-δ interface and SOFC

Sintering aids were commonly used to densify the gadolinium-doped ceria (GDC). In this study, 2 mol% Co(N-O-3)2 center dot 6H(2)O was used as the sintering aid, GDC interlayers with 2 mol% Co(NO3)(2)center dot 6H(2) O (Co-GDC) were sintered at 1150 degrees C, 1200 degrees C, 1250 degrees C and 1350 degrees C, respectively. The Co-GDC interlayer sintered at 1150 degrees C was porous, but only closed pores existed when the Co-GDC interlayers were sintering above 1250 degrees C. The initial ohmic resistances of the cells with Co-GDC interlayers sintered at 1150 degrees C, 1250 degrees C and 1350 degrees C were 0.259, 0.266 and 0.299 Omega cm(2) . After the cells running for 100 h, the ohmic resistances were 0.289, 0.262 and 0.297 Omega cm(2) in turn. The cell with Co-GDC interlayers sintered above 1250 degrees C showed high stability due to the constant ohmic resistance and stable triple phase boundaries (TPBs) of cathode, which were proved by impedance, distribution of relaxation time (DRT) and Scanning Electron Microscope (SEM). Sr migration was fully prevented by the Co-GDC interlayer sintered above 1250 degrees C after the cell operating for 100 h as showed by Energy Dispersive Spectrometer (EDS), which was helpful for the long-term stability of the solid oxide fuel cell.