Study on Nickel Morphological Change at Active Three-Phase-Boundary in Solid Oxide Fuel Cell Anode Using Patterned Nickel-film Electrode

Monday, 24 July 2017
Grand Ballroom East (The Diplomat Beach Resort)
Z. Jiao and N. Shikazono (Institute of Industrial Science, The University of Tokyo)
Patterned nickel-film anode was used in this study to investigate the local morphological changes of nickel during discharge at TPB three-phase-boundary in solid oxide fuel cell anode. Compared to conventional nickel-yttria-stabilized zirconia composite cermet anode, patterned nickel-film anode has the advantages of direct observations at nickel-yttria-stabilized zirconia interface and at three-phase-boundary so that the local morphological changes of nickel can be characterized by scanning electron microscopy. The phenomena of enhanced nickel wettability on yttria-stabilized zirconia surface and nickel spreading on yttria-stabilized zirconia surface at active three-phase-boundary during discharge operation were observed and explained by a proposed model based on the modification of local nickel surface tension by discharge. The nickel-film anode performances and local nickel morphological changes at three-phase-boundary before and after discharges with different conditions were analyzed. The influences of discharge time and overpotential in discharge on local morphological change of nickel and their influences on nickel-film anode performances were also investigated.