Synthesis and properties of Ni-YSZ cermet: anode material for solid oxide fuel cells

Nickel-yttria stabilized zirconia (Ni-YSZ) cermet with various vol.% of 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°C, 2 h. The as-formed cermet powders were fine with surface area in the range of 27–32 m2/g with an average agglomerated particle size in the range of 0.25–0.8 μm.

The samples could be sintered to the required density (>70% theoretical density) with porous microstructure. At lower Ni content (≤30 vol.%) the conductivity increases with increasing temperature whereas at higher nickel content 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 (11.64×10−6 K−1) appears to be compatible with the electrolyte (YSZ) for SOFC application.