SYNTHESIS AND PROPERTIES OF NI-YSZ CERMET - ANODE MATERIAL FOR SOLID OXIDE FUEL-CELLS

Nickel-yttria stabilized zirconia (Ni-YSZ) cermet with various vol.% o f Ni has been prepared by the combustion of Ni(NO3)(2), Y(NO3)(3), ZrO (NO3)(2) and carbohydrazide followed by hydrogen reduction at 800 degr ees C, 2 h. The as-formed cermet powders were fine with surface area i n the range of 27-32 m(2)/g with an average agglomerated particle size in the range of 0.25-0.8 mu m. The samples could be sintered to the r equired density ( > 70% theoretical density) with porous microstructur e. At lower Ni content ( less than or equal to 30 vol.%) the conductiv ity increases with increasing temperature whereas at higher nickel con tent the cermets exhibit metallic behaviour. The thermal expansion of the cermets :increases with increasing Ni content. The 30Ni-YSZ cermet with high electrical conductivity (40 S/cm) and low thermal expansion coefficient (11.64 x 10(-6) K-1) appears to be compatible with the el ectrolyte (YSZ) for SOFC application. (C) Published by Elsevier Scienc e B.V. All rights reserved.