A new symmetric solid oxide fuel cell with a samaria-doped ceria framework and a silver-infiltrated electrocatalyst

A new symmetric SOFC with an SDC framework and a silver-infiltrated electrocatalyst is presented for the first time in this paper. A three-electrode polarization test shows that the Ag-SDC has a low area specific resistance of 1.07 Ω cm² at 600 °C, a low activation energy of 85 kJ mol^-1 and high exchange current densities of 428.2 and 129.0 mA cm^-2 at 750 and 650 °C, respectively, when it is used as an oxygen reduction electrode. It also exhibits low polarization resistance in a humidified hydrogen atmosphere. A symmetric single cell is used in real fuel cell conditions to deliver peak power densities of 200 and 84 mW cm^-2 at 750 and 650 °C, respectively, when humidified hydrogen is used as a fuel and ambient air is used as the cathode atmosphere. The cell still reaches a peak power density of 81 mW cm^-2 at 750 °C when operating on CO. O₂-TPO analysis demonstrates that the Ag-SDC electrode has even better coking resistance than the pure SDC scaffold. The results indicate that Ag-SDCSDCAg-SDC symmetric cells with an infiltrated silver electrocatalyst are a promising new type of fuel cell for use with both hydrogen fuel and carbon-containing fuels.