Performance analysis of cobalt-based cathode materials for solid oxide fuel cell

Abstract

The area specific resistance (ASR) characteristics of Ln(1-x)Sr(x)M ' M1-y"O-y(3-delta) (Ln=Lanthanides, M' and M": transition metal such as Co and Fe), Sm0.5Sr1.5Co1-yNiyO4-delta and Sm0.5Sr1.5Co1-yFeyO4-delta oxides were investigated as cathode materials for intermediate temperature operating solid oxide fuel cell (IT-SOFC) application. As an effect of Sr substitution in A-site of perovskite, ASR of Nd0.5Sr0.5CoO3 (NSC55) was 0.14 Omega cm(2) at 700 degrees C. Sm0.5Sr0.5CoO3-delta (SSC55) on Ce0.9Gd0.1O2-delta (CGO91) and Ce0.8Sm0.2O2-delta (CSO82) showed the lowest ASR as 0.10 Omega cm(2) and 0.085 Omega cm(2) at 700 degrees C among various perovskite compositions in this study. ASR of B-site substituted Pr0.3Sr0.7Co0.3Fe0.7O3-delta (PSCF3737) in the Pr0.3Sr0.7Co1-yFeyO3-delta Was about 0. 13 Omega cm(2) at 700 degrees C. Comparing ASR of SSC55 as a perovskite structure with the value Of Sm0.5Sr1.5Co1-yFeyO4-delta (y=0, 0.3, 0.5 and 0.7) as a spinel structure, the ASR of SSC55 was 0.085 Omega cm(2). However, the value of Sm0.5Sr1.5Co1-yFeyO4-delta (y=0, 0.3, 0.5 and 0.7) was much higher than SSC55 at 700 degrees C. In XPS analyses, the atomic percentage values of PSC55 and PSC37 were 83.5, and 83.1%. However, the value of SrCoO3-delta was 50.2%. The results claim that more oxygen sites including oxygen vacancies on the surface of PSC55 and PSC37 exist than that of SrCoO3-delta (C) 2008 Elsevier B.V. All rights reserved.