Quantitative Study on the Correlation Between Solid Oxide Fuel Cell Ni-YSZ Composite Anode Performance and Sintering Temperature Based on Three-dimensional Reconstruction

The effects of sintering temperatures on the performances and durabilities of conventional nickel-yttria-stabilized zirconia composite solid oxide fuel cell anodes were investigated. The anode microstructures after reduction and 100 hours operation were quantitatively analyzed by three-dimensional reconstruction based on focused ion beam-scanning electron microscopy technique. Percolation of nickel, yttria-stabilized zirconia and pore phases and three phase boundary densities were quantitatively calculated. The anode sintered at 1450°C has been found to show the minimum ohmic resistance and polarization resistance. The differences of ohmic resistances between the anodes can be quantitatively explained by the difference of active three phase boundary density. Besides, the anode sintered at 1450°C could operate without large-scale channel cracks which may cause damage and relatively fast degradation. The lowest degradation rate of anode sintered at 1450°C is attributed to the strengthened YSZ network for maintaining Ni phase percolation compared to the other two sintering temperatures.