Preparation and Characterization of Nanoceramics for Solid Oxide Fuel Cells

Resumo

Precursor powders in the ZrO₂–HfO₂–Y₂O₃–CeO₂, In₂O₃–ZrO₂, and NiO–Nd₂O₃ systems for components of solid oxide fuel cells have been prepared by liquid-phase synthesis. We have determined formation conditions and the particle size of ZrO_2- and In₂O_3-based solid solutions and neodymium nickelate (Nd₂NiO₄), demonstrated the feasibility of producing nanocrystalline powders (10–30 nm) of tailored chemical composition in the temperature range 500–900°C, and optimized powder consolidation conditions. Nanoceramics with a crystallite size from 60 to 90 nm have been obtained and their microstructure and phase composition have been investigated. We have studied the electrical properties of the ZrO_2- and In₂O_3-based solid solutions and the Nd₂NiO₄ compound and established the range of their electrical conductivity at temperatures from 300 to 1000°C: 2.27 × 10^–3 to 2.51 S/cm for the ZrO₂-based solid solution, 8.91 × 10¹ to 6.59 × 10³ S/cm for the In₂O₃-based solid solution, and 3.98 × 10² to 5.02 × 10² S/cm for Nd₂NiO₄.