Electrochemical properties and durability of in-situ composite cathodes with SmBa0.5Sr0.5Co2O5+δ for metal supported solid oxide fuel cells

The authors are grateful for the support of the Basic Science Research Program, part of the National Research Foundation of Korea (NRF), funded by the Ministry of Science, ICT and Future Planning (No. 2014R1A1A1004163). The electrochemical properties and long-term performance of an in-situ composite cathode comprised of SmBa0.5Sr0.5Co2O5+δ (SBSCO) and Ce0.9Gd0.1O2−δ (CGO91) are investigated for metal supported solid oxide fuel cell (MS-SOFC) application. The Area Specific Resistance (ASR) of an in-situ composite cathode comprised of 50 wt% of SBSCO and 50 wt% of CGO91 (SBSCO:50) is 0.031 Ω cm2 in the first stage of measurement at 700 °C; this value of ASR increases to 0.138 Ω cm2 after 1000 h. The ASR of SBSCO:50 (in-situ sample at 750 °C) is 0.014 Ω cm2 at the initial stage of measurement; the increase of ASR after 1000 h at 750 °C is only 0.067 Ω cm2. These results suggest that the optimum temperature for in-situ firing of an SBSCO:50 cathode sample of MS-SOFC is higher than 700 °C, ideally around 750 °C. Postprint