Solid oxide fuel cells (SOFCs) were fabricated with thick Ce0.9 Gd0.1 O1.95 (GDC) electrolytes, composite anodes containing La0.8 Sr0.2 Cr0.98 V0.02 O3-δ (LSCV), GDC, and NiO, and Au current collector grids. SOFCs with varying anode firing temperatures, GDC contents, and NiO contents were structurally evaluated and characterized by current-voltage measurements and electrochemical impedance spectroscopy in humidified hydrogen and air. With increasing anode firing temperature, particle sizes in the porous anodes increased and the area specific resistance (RAS) increased (power density decreased). For lower firing temperatures, e.g., 1100°C, RAS decreased sharply with increasing NiO content from 0 to 5 wt %, but showed little further decrease from 5 to 20 wt % NiO. RAS values were generally higher for higher firing temperatures, e.g., 1400°C, decreasing gradually with increasing NiO content from 0 to 20 wt %. These trends were explained by an increase in Ni particle sizes with increasing firing temperature, making the Ni catalyst less effective. The anode polarization resistance at 750°C was ∼0.8 cm2 at 450 mV cell voltage (0.1 cm2 at open circuit), for a composition of 47.5 wt % LSCV, 47.5 wt % GDC, and 5 wt % NiO.
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Renewable Energy, Sustainability and the Environment
- Surfaces, Coatings and Films
- Materials Chemistry