Supported Zr(Sc)O2 SOFCs for reduced temperature prepared by slurry coating and co-firing

With an aim of reducing the operation temperature of solid oxide fuel cells (SOFCs), we examined the feasibility of Sc2O3–ZrO2 (SSZ) as electrolyte in working at intermediate temperatures. The SSZ cells were prepared by a co-firing process. Ni–SSZ cermet anode was adopted to support the cell. Thin green electrolyte films of SSZ were prepared onto Ni–SSZ anode substrate by a dip-coating technique and then co-fired. Pt–SSZ cermet was used as cathode. The cell was tested with humidified hydrogen as fuel and air as oxidant at 700, 800 and 900 °C. The test cell showed power density of 0.38 W/cm2 at 700 °C and 0.8 W/cm2 at 800 °C. The cathodic resistance of the test cell amounted about 80% of the total resistance at 700 °C as was identified by an AC impedance measurement. It was found that cell performance would be improved by controlling microstructure of the anode substrate and increasing the cathode activity.