Plasma-Sprayed Coating of an Apatite-Type Lanthanum Silicate Electrolyte for Intermediate Temperature Solid Oxide Fuel Cells (IT-SOFCs)

Apatite-type lanthanum silicate was successfully synthesized via a solid state reaction protocol at 1400 °C in a vacuum for 4 hours. The powder was synthesized faster and at a lower reaction temperature than by conventional solid state reaction methods. The resulting powder was used in the fabrication of a coating deposited by atmospheric plasma spray (APS) technology. The microstructure of the coating was analyzed by X-ray diffraction and scanning electron microscopy. Heat treatment was found to fully crystallize the coating, increasing its density. The ionic conductivity of the apatite coating was 0.39 (0.054) mS/cm at 850 (700) °C, and its activation energy was 0.67 eV.