Performance and stability analysis of SOFC containing thin and dense gadolinium-doped ceria interlayer sintered at low temperature

Gadolinium-doped ceria (GDC) interlayers are required to prevent the interfacial reaction between La0.6Sr0.4Co0.2Fe0.8O3 (LSCF) cathode and Y2O3-stabilized ZrO2 (YSZ) electrolyte in solid oxide fuel cells (SOFCs). However, it's difficult to prepare a thin and dense GDC interlayer on the sintered half-cell at a low temperature. In this study, the physical vapor deposition (PVD) method was employed to successfully manufacture dense GDC interlayers with the thickness of 1 mm. The influences of GDC sintering temperature (900 degrees C, 1000 degrees C and 1100 degrees C) on cell performance characteristics and degradation behavior were investigated. The cell with GDC interlayer sintered at 1100 degrees C showed the lowest degradation rate during the 216-h operation. The best stability was attributed to the most effective inhibition of Sr diffusion by the GDC interlayer, which was demonstrated by the almost unchanged Ohmic and polarization resistances during the aging stage and the negligible Sr enrichment at YSZ/GDC interface. Compared to the conventional screen-printed GDC interlayers (sintered above 1250 degrees C), the GDC interlayer prepared by the PVD method and sintered at 1100 degrees C was significantly denser and thinner, showing a promising application prospect due to its benefits for cell stability. (C) 2021 The Chinese Ceramic Society. Production and hosting by Elsevier B.V.