High-temperature proton conductor BaZr0.7Pr0.1Y0.2O3-delta (BZPY) was investigated as electrolyte for intermediate temperatures (400-800 degrees C) solid oxide fuel cells (IT-SOFCs), which exhibited excellent chemical stability in atmospheres containing CO2 and water vapor. In addition, both La0.4Sr0.6Co0.2Fe0.8O3-delta-BaZr0.7Pr0.1 lY(0.2)O(3-delta) (LSCF-BZPY) and La0.4Sr0.6Co0.2Fe0.8O3-delta-Ce0.8SM0.2O1.9 (LSCF-SDC) composite oxides were fabricated and evaluated as working cathodes for anode-supported IT-SOFCs based upon thin BZPY electrolytes. The single cells with LSCF-BZPY cathode showed the maximum power density of 86.7 mW cm(-2) at 700 degrees C and the calculated activation energy was 91.19 kJ mol(-1). While the cells with LSCF-SDC cathode exhibited the higher maximum power density of 112.4 mW cm(-2) at 700 degrees C and the calculated activation energy was 101.61 kJ mol(-1). The experimental results indicated that proton electron mixed conducting composite cathodes are more promising and beneficial than oxygen-ion electron mixed conducting composite cathodes for proton-conducting SOFCs during actual low operating temperatures.

Intermediate temperature solid oxide fuel cells; Chemical stability; Proton electron mixed conductor; Oxygen-ion electron mixed conductor

University of Science and Technology of China; Institute of Multidisciplinary Research for Advanced Materials, Tohoku University; Department of Material Science and Chemistry, China University of Geoscienceity of Geoscience; Huainan Normal University