Optimization of electrode-electrolyte interface structure for solid oxide fuel cell cathode

摘要

A numerical method is developed to optimize the shape of electrode-electrolyte interface for maximizing the electrochemical performance of solid oxide fuel cells (SOFCs). The electrode-electrolyte interface structure is chosen as the design variable to be optimized, and the total amount of reaction current in the electrode is maximized as the objective function. Adjoint method is used to compute the sensitivity of the design parameter on the objective function, i.e. the sensitivity of the interface shape on the total reaction current is investigated. In this study, pure La0.6Sr0.4Co0.2Fe0.8O3 (LSCF) cathode and Gd0.1Ce0.9O1.95 (GDC) electrolyte is chosen for the design target. Both LSCF/pore double phase boundary (DPB) reaction and LSCF/GDC/pore triple phase boundary (TPB) reaction are considered. It is found from the computational results that the cathode with optimized electrode-electrolyte interface structure largely enhances the reaction current than the flat electrode-electrolyte interface. Finally, the sensitivities of the optimal sturcture on the conductivities and reaction rates are investigated.