Microstructural evolution-driven degradation of nickel-based SOFC anodes: Insights from mesoscale modeling

Degradation mechanisms in nickel-based anode composites (Ni/YSZ and Ni/CGO) critically influence the electrochemical performance and durability of solid oxide fuel cells (SOFCs). Despite notable advances, the complex relationship between morphological evolution and long-term electrochemical degradation in nickel-based electrodes remains insufficiently clarified. This study introduces a novel mesoscale modeling framework that integrates phase-field modeling (PFM) and the lattice Boltzmann method (LBM) to quantitatively predict long-term performance evolution. The developed PFM elucidates compositional and microstructural evolution within the electrode, capturing intricate phase boundary dynamics. Concurrently, the LBM rigorously evaluates electrochemical reaction pathways and charge transfer resistances, offering a multi-physics perspective on performance degradation. The model is rigorously validated using the MAD (Median Absolute Deviation), with errors of only 1.8%, 2.43%, and 4.1% for the initial electrode structure, activation overpotential, and particle size growth, respectively. Through systematic parametric studies, this work quantifies the influences of initial particle size and volume fraction on the interplay between degradation and electrochemical performance. In the case of nickel-based electrodes, a higher volume fraction of the ion-conducting phase led to the maximum evaluation scores, reaching 47.8% and 44.2%, respectively. These findings establish a robust performance evaluation framework, providing critical insights into the synergistic effects of microstructural evolution on electrode durability and establishing a foundation for rational design of next-generation SOFC anodes.