Stable Single-Chamber Solid Oxide Fuel Cells Based on Doped Ceria Electrolytes and $La0.5Sr0.5CoO3$ as a New Cathode

Several cathodes working in hydrocarbons diluted atmospheres have been proposed for single-chamber solid oxide fuel cells (SOFCs) fabrication. But, few cathodes work well in propane. In this work, we propose a new stable cathode of $La0.5Sr0.5CoO3$ (LSCO) for the single-chamber SOFCs, which works well in diluted propane atmospheres. For this purpose, powders of $Ce0.8Gd0.2O1.9$ (CGO) for electrolytes and powders of (LSCO) for cathodes were prepared by sol-gel related techniques as pentadionate methods. These methods consist of preparing a solution from the acetates or pentadionates followed by a jellification. Then, the decomposition of the organic molecules is initiated, obtaining nanometric powders of the abovementioned compounds. In this way, we have obtained high purity powders of CGO and LSCO as confirmed by x-ray diffraction powder analysis. Microstructure was analyzed by SEM and TEM microscopy, the analysis of the powders obtained by sol-gel techniques shows a nanometric size grain $(∼30nm)$ and reactivity for sintering was studied in detail. Very high-density electrolytes (⁠$∼95-99%$ of theoretical density) were obtained with better power density currents than in samples prepared by solid-state reaction samples. Uniaxial pressing ceria based electrolytes were prepared from these powders and characterized in one chamber reactor using propane as fuel and $LSCO+CGO$ as cathode. Anodes were prepared from $Ni+CGO$ mixtures. Different gas mixtures of propane and air were prepared and tested at different flow rates in order to optimize electrical properties. Stable single-chamber fuel cells working in diluted propane atmospheres could be prepared with these materials.