Ln1?xSrxCoO3 (Ln=Gd, Pr) as a cathode for intermediate-temperature solid oxide fuel cells?

• Published in: Solid state ionics 2004-11, Vol.175 (1-4), p.59-61
• Main Author: ROSSIGNOL, C
• Format: Article
• Language: English
• Subjects: Chemical Sciences; Material chemistry
• ISSN: 0167-2738; 1872-7689
• DOI: 10.1016/j.ssi.2004.09.021

Researchers at Argonne National Laboratory have tested several cathodes on yttria-stabilized zirconia (YSZ) and gadolinia-doped ceria (CGO) electrolytes for use in solid oxide fuel cells (SOFCs). The Pr0.5Sr0.5CoO3 (PSC) and Gd0.5Sr0.5CoO3 (GSC) cathodes show the best performance on CGO, achieving an area-specific resistance (ASR) between 0.1 and 0.2 Omega*cm2 at 650 deg C. However, the desirable operating temperature for CGO is between 500 and 600 deg C, where the ASRs remain very high. The cobalt-based materials in contact with the YSZ electrolyte exhibit severe reactions. To prevent these reactions, a dense interlayer of CGO has been added between the YSZ and the cobalt-based cathodes. The results for the PSC and GSC cathodes on the YSZ electrolyte protected by a CGO layer reveal ASR values between 0.1 and 0.2 Omega*cm2 at 750 deg C and 0.3 Omega*cm2 at 700 deg C. Long-term testing of both PSC and GSC cathodes on YSZ electrolytes with CGO interlayers showed stable ASR values for 500 h at 800 deg C. Thermal cycling between room temperature and 800 deg C after long-term testing showed minimal degradation.