Simulation of Nickel Morphological and Crystal Structures Evolution in Solid Oxide Fuel Cell Anode Using Phase Field Method

In the present study, a phase field method is used to simulate the morphological and crystal structural evolution of nickel-yttria stabilized zirconia composite anode of solid oxide fuel cell based on three-dimensional microstructures reconstructed by focused ion beam-scanning-electron-microscopy technique. A three-dimensional reconstruction of the anode sample after initial reduction is used as the initial microstructure. In order to simulate the nickel crystal grain growth and the corresponding morphological change at the same time, both material composition and crystallographic orientation order parameters are introduced in the model. In order to quantitatively study the nickel coarsening effect on anode performance, the evolution of three-phase boundary density and nickel specific surface area are quantitatively calculated in the simulations. Simulation results reproduced well the initial microstructural evolution in the experiments.