PRODUCTION OF NI OR NIO/YSZ COMPOSITE POWDER, AND FORMATION OF FUEL ELECTRODE MEMBRANE USING THE SAME

摘要

PROBLEM TO BE SOLVED: To produce NiO/YSZ composite powder having improved uniformity of the compsn. and texture of the powder and suitable for use as a fuel electrode by synthesizing and compacting a powdery mixture of nickel oxide and yttria doped zirconia (YSZ) and heat-treating the resultant green compact. SOLUTION: A powdery mixture of nickel oxide and yttria doped zirconia contg. 60-95 mol.% NiO and 3-20 mol.% Y2 O3 is synthesized by coprecipitation using water-soluble metallic salts such as nitrates, sulfates, carbonates or chlorides as starting materials. The precipitate is dried, comminuted, heat-treated (calcined) at 700 deg.C for 10 hr and compacted under =1 kgf/mm2 pressure. The resultant green compact is heat-treated at 1,200-1,600 deg.C for 5 hr to obtain the objective NiO/YSZ composite powder. This composite powder is comminuted to 0.2-50 m particle size distribution and slurried with a slightly volatile solvent and the objective fuel electrode membrane is formed by a slurry coating method in the upper layer part of an interfacial layer on a dense solid electrolyte membrane.