Assessment of Reoxidation-Driven Interfacial Delamination and Associated Performance Degradation in Solid Oxide Fuel Cells

Abstract The low reliability of anode-supported solid oxide fuel cells (ASOFCs) under reoxidation severely limits their commercialization. Among degradation mechanisms, interfacial delamination induced by reoxidation of Ni-based anodes is a key driver of performance deterioration. Here, the reoxidation process is reformulated as an intrinsic material state variable. A cohesive zone model (CZM) describes the initiation and propagation of the resulting interfacial delamination, and the mixed-mode cohesive parameters of the interface are experimentally calibrated through four-point bending tests. The resulting delamination is further integrated with a computational fluid dynamics (CFD) model to reveal the influence of interfacial structural evolution on the electrochemical behavior of the cell. The results show that delamination initiates when the oxidation degree reaches 0.23 and increases to 26.4% under complete reoxidation. Within the retained-anode-activity assumption adopted in the electrochemical assessment, this structural damage amplifies transport-related ohmic polarization and induces localized deactivation of electrochemical reactions, ultimately leading to a delamination-related maximum power output loss of 20.39%. The study establishes an experimentally calibrated CZM-CFD integrated analysis framework that enables quantitative characterization of reoxidation-induced interfacial delamination and associated performance degradation, evaluates the regulatory potential of multiscale engineering parameters on delamination evolution, and provides guidance for assessment, structural design, and mitigation of reoxidation degradation in ASOFCs engineering applications.