Preparation and characteristics of Ni/YSZ cermet anodes by vapor-phase deposition

High performance nickel/yttria-stabilized zirconia (Ni/YSZ) anodes were prepared by a novel vapor-phase method. The vapor-deposited Ni/YSZ cermets were prepared by reacting surface-oxidized nickel with zirconium and yttrium chlorides using nickel oxide as an oxygen source, After the vapor-phase reaction, it was found that nickel grains of the cermets are covered with porous YSZ layer. In the present work, the morphology and polarization behaviors of the vapor-deposited Ni/YSZ cermet anodes were compared with those of the conventional slurry-coated Ni/YSZ cermets, The steady-state polarization and AC complex impedance measurements indicated that the vapor-deposited Ni/YSZ cermets show lower anodic polarization than the cermets prepared by the conventional slurry method. This decrease in the polarization was attributed to an increase of electrochemical active sites, three-phase-boundary, in the vapor-deposited Ni/YSZ cermet anodes.