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

The area specific resistance (ASR) characteristics of Ln1 − xSrxM′1 − yM″yO3 – δ (Ln=Lanthanides, M′ and M″: transition metal such as Co and Fe), Sm0.5Sr1.5Co1 − yNiyO4 – δ and Sm0.5Sr1.5Co1 − yFeyO4 – δ oxides were investigated as cathode materials for intermediate temperature operating solid oxide fuel cell (IT-SOFC) application. effect of Sr substitution in A-site of perovskite, ASR of Nd0.5Sr0.5CoO3 (NSC55) was 0.14 Ω cm2 at 700 °C. Sm0.5Sr0.5CoO3 – δ (SSC55) on Ce0.9Gd0.1O2 – δ (CGO91) and Ce0.8Sm0.2O2 – δ (CSO82) showed the lowest ASR as 0.10 Ω cm2 and 0.085 Ω cm2 at 700 °C among various perovskite compositions in this study. ASR of B-site substituted Pr0.3Sr0.7Co0.3Fe0.7O3 – δ (PSCF3737) in the Pr0.3Sr0.7Co1 − yFeyO3 – δ was about 0.13 Ω cm2 at 700 °C. Comparing ASR of SSC55 as a perovskite structure with the value of Sm0.5Sr1.5Co1 − yFeyO4 – δ (y = 0, 0.3, 0.5 and 0.7) as a spinel structure, the ASR of SSC55 was 0.085 Ω cm2. However, the value of Sm0.5Sr1.5Co1 − yFeyO4 – δ (y = 0, 0.3, 0.5 and 0.7) was much higher than SSC55 at 700 °C. analyses, the atomic percentage values of PSC55 and PSC37 were 83.5, and 83.1%. However, the value of SrCoO3 – δ 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 – δ.