Simulation of the reduction process of solid oxide fuel cell composite anode based on phase field method

• A model is proposed to simulate the reduction process of NiO in SOFC anode.
• Volume change and Ni sintering determine the initial Ni microstructure.
• Phase field width can be changed to modify the sintering speed in simulation.

It is known that the reduction process influences the initial performances and durability of nickel-yttria-stabilized zirconia composite anode of the solid oxide fuel cell. In the present study, the reduction process of nickel-yttria stabilized zirconia composite anode is simulated based on the phase field method. An three-dimensional reconstructed microstructure of nickel oxide-yttria stabilized zirconia composite obtained by focused ion beam-scanning electron microscopy is used as the initial microstructure for the simulation. Both reduction of nickel oxide and nickel sintering mechanisms are considered in the model. The reduction rates of nickel oxide at different interfaces are defined based on the literature data. Simulation results are qualitatively compared to the experimental anode microstructures with different reduction temperatures.