Optimisation and Evaluation of La 0.6 Sr 0.4 CoO 3 – δ Cathode for Intermediate Temperature Solid Oxide Fuel Cells

In this work, La 0.6 Sr 0.4 CoO 3 – δ /Ce 1 – x Gd x O 2 – δ (LSC/GDC) composite cathodes are investigated for SOFC application at intermediate temperatures, especially below 700 °C. The symmetrical cells are prepared by spraying LSC/GDC composite cathodes on a GDC tape, and the lowest polarisation resistance ( R p ) of 0.11 Ω cm 2 at 700 °C is obtained for the cathode containing 30 wt.‐% GDC. For the application on YSZ electrolyte, symmetrical LSC cathodes are fabricated on a YSZ tape coated on a GDC interlayer. The impact of the sintering temperature on the microstructure and electrochemical properties is investigated. The optimum temperature is determined to be 950 °C; the corresponding R p of 0.24 Ω cm 2 at 600 °C and 0.06 Ω cm 2 at 700 °C are achieved, respectively. An YSZ‐based anode‐supported solid oxide fuel cell is fabricated by employing LSC/GDC composite cathode sintered at 950 °C. The cell with an active electrode area of 4 × 4 cm 2 exhibits the maximum power density of 0.42 W cm –2 at 650 °C and 0.54 W cm –2 at 700 °C. More than 300 h operating at 650 °C is carried out for an estimate of performance and degradation of a single cell. Despite a decline at the beginning, the stable performance during the later term suggests a potential application.