Quantitative study on solid oxide fuel cell anode microstructure stability based on 3D microstructure reconstructions

摘要

It is well known that nickel coarsening plays an important role in influencing the performance degradation of solid oxide fuel cell nickel-yttria-stabilized zirconia composite anode during long-term operation. Different anode microstructures fabricated by identical nickel oxide-yttria-stabilized zirconia powder mixture are reconstructed using dual-beam focused ion beam-scanning electron microscopy technique in this work. The nickel coarsening processes in nine anode microstructures are simulated using phase field method in order to quantitatively investigate the influences of nickel coarsening on the stability of a specific composite anode during long-term operation. Based on the simulation results, time-dependent evolutions of triple-phase-boundary density, specific nickel surface are and nickel-yttria-stabilized zirconia interfacial area, isolated nickel volume fraction, and tortuosity factors of different phases are quantified and compared. The simulation results show the possibility that the sintering scheme and reduction process of the anode can be optimized to enhance the anode performance and stability during long-term operation.