Investigations on the microstructural degradation and mechanical response of Ni–CGO anodes using phase-field method and stochastic modeling

The microstructural degradation of Ni–CGO anodes in solid oxide fuel cells affects both electrochemical and mechanical properties. This study presents an automated workflow to quantify the evolution of geometrical descriptors and their influence on effective mechanical properties. Three-dimensional anode microstructures were aged up to 35,000 h using phase-field and stochastic modeling, followed by mechanical loading simulations. Aging caused microstructural coarsening as the mean pore diameter increased, while pore specific surface area and triple-phase boundary density decreased. Effective elastic moduli also decreased with aging. While the average von Mises stress remained nearly constant, the critical volume fraction increased with aging. Within the studied microstructures, the effective Hill modulus was strongly related to pore volume fraction and pore specific surface area. The critical volume fraction related positively with pore diameter and inversely with pore specific surface area and triple-phase boundary density.