Lattice-Boltzmann modeling of gas transport in Ni-Yttria-stabilized zirconia anodes during thermal cycling based on X-ray computed tomography

The thermal cycling treatment of Ni-Yttria-stabilized zirconia (Ni-YSZ) anodes strongly influences their three-dimensional (3D) microstructure, including their interior connectivity, phase size and three-phase boundary (TPB) density. In this paper, a nondestructive imaging technology based on X-ray computed tomography is used to obtain the 3D microstructure of Ni-YSZ anode samples after thermal cycling. The lattice Boltzmann method (LBM) is used to simulate gas transport in these 3D microstructures. The mole fraction distributions of gases through the 3D connected pore phase are obtained from the simulated results, enabling the concentration polarization to be calculated. Moreover, the active-TPB density is associated with an electrochemical reaction to simulate the mass diffusion. These results may elucidate the relationship between the microstructure and electrochemical properties.