Preparation of NiO-YSZ Composite Powder Through 2-Step Hydrothermal Synthesis and Its Application to Solid Oxide Fuel Cell Anode Functional Layer.

NiO-YSZ composite powders were prepared by 2-step hydrothermal synthesis and applied as an anode functional layer to improve the performance of SOFCs. The precursor solution containing yttrium chloride, zirconium oxychloride, and nickel nitrate was hydrothermally treated at 100-130 degrees C for 36 h and then calcined at 900 degrees C for 4 h. The results of X-ray diffraction, Field-Emission Scanning Electron Microscope and Transmission Electron Microscope showed that the NiO (50-100 nm) and YSZ (200-300 nm) were successfully synthesized and these two phases were well separated with the weak agglomeration. Electrical conductivity of the cermet made from the powders produced by 2-step hydrothermal synthesis was much higher than that of the cermet prepared by ball milling. A single cell with anode functional layer showed a maximum power density of 1.7 W/cm2 at 800 degrees C, which may be owing to the homogeneous distribution and the small particle size of the obtained powders.