Evaluation of Ni-YSZ Anode Degradation during Redox Cycling

Degradation of Solid Oxide Fuel Cell (SOFC) anode under redox cycling was evaluated by microstructure change measurements and overpotential calculations using a Lattice Boltzmann method (LBM). Microstructures were obtained by Focused Ion Beam Scanning Electron Microscopy (FIB-SEM) reconstruction technique. In the overpotential calculation, exchange current density and Yttria stabilized Zirconia (YSZ) ionic conductivity were considered as degradation factors. Numerical simulation reproduced well the decrease of overpotential just after the redox treatment and the increase after subsequent discharge process. This is consistent with the experimental result. However, simulation result showed lower overpotential values than the experiment after 10 redox cycles. Deterioration of exchange current density and YSZ ionic conductivity are considered as the reason for the degradation after redox cycles.