A new method of preparing Ni/YSZ cermet materials

Ceramic–metal composites (cermets) containing yttria-stabilized zirconia(YSZ) and Ni particles as anode materials in solid oxide fuel cells were prepared by a new method. The method encompasses nickel oxalate dihydrate precipitation on the nanometre YSZ powder, and decomposition at 633 K in inert atmosphere. The composite powders containing 30, 40, and 50% Ni manufactured by the oxalate method were compacted into disk pellets, and sintered in Ar containing 10% H2. The structure of the cermet materials was characterized by means of X-ray diffractometry (XRD), scanning electron microscopy (SEM), and mercury porosimetry. The thermal expansion coefficient (TEC) was determined by the dilatometric method. Electrochemical impedance spectroscopy (EIS) was used to determine electrical conductivity. The oxalate method leads to obtaining the Ni/YSZ anodes with the Ni content reduced to 40 wt% and well obeying based requirements for anode material in SOFCs.