BACE_0.85Y_0.15O_3-ΔBASED MATERIALS FOR SOLID OXIDE FUEL CELLS: ROOM-TEMPERATURE NEUTRON DIFFRACTION STUDY

Abstract

Abstract. The crystal structure of oxygen-deficient BaCe0.85Y0.15O3−δ (BCY15) materials prepared by auto-combustion with following calcination at high temperature was determined from neutron and X-ray powder diffraction. The materials were used recently as cathode, anode and central membrane in a novel design of SOFC: dual membrane fuel cell (dmFC). The dmFC design exploits the good mixed (protonic and oxide ion) conductivity in BaCe 0.85Y0.15O2.825 at working temperatures of 600-700 o C. It allows the introduction of a separate compartment (central membrane) for water formation and evacuation. The central membrane has mixed ionic conductivity ensured by a composite material and porous microstructure. Profile refinements within the orthorhombic space group Pnma reproduced the neutron diffraction profiles of all the materials (dense, porous, powder) based on BCY15 conductivity presenting similar model crystal structures to protonic conductor BaCe 0.9Y0.10O2.95 and the parent undoped BaCeO3 perovskite.