PREPARATION AND CHARACTERISTICS OF NI YSZ CERMET ANODES BY VAPOR-PHASE DEPOSITION/

High performance nickel/yttria-stabilized zirconia (Ni/YSZ) anodes wer e prepared by a novel vapor-phase method. The vapor-deposited Ni/YSZ c ermets were prepared by reacting surface-oxidized nickel with zirconiu m and yttrium chlorides using nickel oxide as an oxygen source, After the vapor-phase reaction, it was found that nickel grains of the cerme ts are covered with porous YSZ layer. In the present work, the morphol ogy and polarization behaviors of the vapor-deposited Ni/YSZ cermet an odes were compared with those of the conventional slurry-coated Ni/YSZ cermets, The steady-state polarization and AC complex impedance measu rements indicated that the vapor-deposited Ni/YSZ cermets show lower a nodic polarization than the cermets prepared by the conventional slurr y method. This decrease in the polarization was attributed to an incre ase of electrochemical active sites, three-phase-boundary, in the vapo r-deposited Ni/YSZ cermet anodes.