Fabrication of Porous Ni-ZrO2 for SOFC Using NiO-ZrO2 Composite Powders

Porous NiZrO2 has been widely used as anode in SOFC. However, it has been reported that there was reduction in cell performance at high temperature since Ni grains in the porous Ni ZrO2 sintered during cell operation. In this study, NiOZrO2 composite powders in which NiO powder were covered with ZrO2 particles were prepared with controlled microstructure of porous NiZrO2 which can prevent sintering of Ni grains during cell operation. NiOZrO2 composite powders (HNZ) were prepared using NiO powder of high specific surface area and ZrO2 sol of average particle size of 50 nm by ball milling (sol-coating method). SEM and EPMA analysis of prepared NiOZrO2 composite powders showed that NiO particles were covered with ZrO2 particles. The crystallite phases, crystallite sizes, BET specific surface area of NiOZrO2 composite powders and porosities of fabricated porous NiZrO2 were characterized. SEM and EPMA analysis showed that ZrO2 was distributed around Ni of a few μm range in the porous Ni ZrO2 (HNZ) fabricated by the sol-coating method. Mechanical properties of porous NiZrO2 (HNZ) are required to be improved.