Study on the effects of polarization on local morphological change of nickel at active three-phase-boundary using patterned nickel-film electrode in solid oxide fuel cell anode

In this study, patterned nickel-film electrode was used to investigate the effects of polarization on local morphological changes of nickel at three-phase-boundary in solid oxide fuel cell anode. Compared to conventional porous composite nickel-yttria-stabilized zirconia composite cermet anode, patterned nickel-film anode facilitates the direct observations at nickel-yttria-stabilized zirconia interface and three-phase-boundary so that the local morphological changes of nickel can be qualitatively characterized by scanning electron microscopy. The phenomena of enhanced nickel wettability and nickel spreading on yttria-stabilized zirconia surface at active three-phase-boundary under polarization were observed and explained by a model based on the modification of local nickel surface tension. The nickel-film anode performances and local nickel morphological changes at three-phase-boundary before and after operations with different conditions were analyzed. The influences of operation time and anode overpotential variation on local morphological change of nickel were investigated.