Effect of Co-Doped GDC Buffer Layer on the Power Density of Solid Oxide Fuel Cell (SOFC)

It is usually accepted that the doped ceria buffer layer is needed between the conventional yttria-stabilized zirconia (YSZ) electrolytes and the Fe and Co containing cathode materials such as (La,Sr)(Co,Fe)O_3-δ (LSCF) to improve the cell performance and to prevent unwanted chemical reactions between them. In this study, the effect of the sintering temperature, cobalt doping amount, and the starting powders of GDC (Gadolinium Doped Ceria) layer were investigated. The cell testing result indicated that it would be desirable to decide the sintering temperature of the GDC layer less than 1250°C to minimize the effect of the solid solutions based on (Zr, Ce)O₂. Furthermore, 5 days operations of the button cell with cobalt doped GDC layer showed the increased ohmic and polarization resistance, indicating the cobalt segregation from the GDC layer during the long term operation.