Effect of components in electrodes on sintering characteristics of Ce0.9Gd0.1O1.95 electrolyte in intermediate-temperature solid oxide fuel cells during fabrication

The effects of anode and cathode components on solid-state reaction and sintering characteristics of Ce0.9Gd0.1O1.95 (CGO) electrolyte were investigated in the temperature range from 900 to 1200 °C. The solubility limit of components in the anode was <4 mol% for 1/2Fe2O3, <1 mol% for NiO, and <3 mol% for CuO. The solubility limit of components in the cathode was <4 mol% for 1/2La2O3, <4 mol% for SrO, and <1 mol% for 1/3Co3O4. A small amount of addition of Fe2O3, Co3O4 or CuO remarkably enhanced the sintering characteristics of the CGO nanopowder. NiO, La2O3 or SrO addition lowered. In the case of the mixture of the CGO and La0.6Sr0.4CoO3, enhancement of sintering characteristics of the CGO and no reaction products were observed. From scanning electron microscopy observation, the sintered CGO samples with Fe2O3 showed the feature by solid-state sintering mechanism. For the CGO with CuO, the samples showed the trace of liquid-phase sintering. The samples of CGO with Co3O4 included large grains, which seem to relate to cobalt vapor from the cobalt oxide particles.