Cone-shaped cylindrical Ce0.9Gd0.1O1.95 electrolyte prepared by slip casting and its application to solid oxide fuel cells

A cone-shaped gadolinium doped ceria (Ce0.9Gd0.1O1.95, GDC) electrolyte cylinder with a thin wall was fabricated using slip casting technique. The diameter of the larger open end of the cone-shaped cylinder was 0.85 cm, the length was 1.0 cm, and the thickness of the wall was 0.026 cm after sintering. Both the electrolyte and electrode powders were fabricated by using a glycine-nitrate process. A single solid oxide fuel cell (SOFC) was prepared with the cone-shaped electrolyte, NiO-GDC (70:30 wt.%) anode and Sm0.5Sr0.5CoO3 (SSC) cathode. Its electrochemical performance (I-V curve) and electrochemical impedance spectroscopy (EIS) were studied with humidified hydrogen as the fuel and air as the oxidant. The maximum output power density was about 300 mW/cm2 at 700 °C. The EIS results showed that the dominant loss of the SOFC was from the ohmic resistance of the electrolyte.