Ni coarsening in Ni-yttria stabilized zirconia electrodes: Three-dimensional quantitative phase-field simulations supported by ex-situ ptychographic nano-tomography

In-depth understanding of nickel (Ni) coarsening is helpful for improving the service life of Ni-yttria stabilized zirconia (YSZ) electrodes in solid oxide cells. Unfortunately, very few quantitative experimental/theoretical descriptions of Ni coarsening in Ni-YSZ electrodes during long-term operation exist. In this paper, quantitative modeling of Ni coarsening in Ni-YSZ electrodes was achieved through three-dimensional (3D) phase-field simulation supported by ex-situ ptychographic nano-tomography and input of reliable thermophysical parame-ters. A pragmatic procedure was proposed to refine and verify the materials parameters for the simulations. Moreover, the microstructures of the Ni-YSZ electrode in the pristine and annealed states obtained via the ex-situ ptychographic nano-tomography were used as the initial input and experimental validation for the phase-field simulations. After that, comprehensive comparison between the simulated and the experimental 3D micro-structures was conducted, indicating the successful quantitative phase-field simulation of Ni coarsening in Ni-YSZ electrodes presented here. The success of this work is expected to pave the way for accurate prediction of the service life and even design of high-performance Ni-YSZ electrodes.