GDC Diffusion Layer for Improving Electrochemical and Mechanical Property of the Intermediate Temperature Solid Oxide Fuel Cell

Abstract

The yttrium stabilized zirconia (YSZ) electrolyte with La0.6Sr0.4Co0.2Fe0.8O3 (LSCF) cathode system was studied for the intermediate temperature solid oxide fuel cell which operate 650℃. However, the reaction that occurs at the interface of YSZ electrolyte and LSCF creates the insulating layer. In this study, to prevent the reaction, 500nm thickness of Ce0.9Gd0.1O2−δ (GDC) diffusion layer was loaded at the surface of the YSZ electrolyte by dip coating method and it effectively limited the creation of the secondary phase. Also, more connecting points with LSCF cathode were created and it improved the conductivity and the mechanical wettability with LSCF cathode. Before and after operating, the microstructure of the surface and cross-section were observed with Scanning Electron Microscopy (SEM) analysis. The creation of the secondary phase and composition of each layer were examined by Energy Dispersive X-ray Spectroscopy (EDS) mapping. The Electrochemical Impedance Spectroscopy (EIS) plot showed that when the GDC diffusion layer was loaded the ohmic and polarization resistances were significantly decreased. Current-Voltage curve (IV-curve), Power density and Electrochemical Impedance Spectroscopy (EIS) were measured and it demonstrated the enhanced performance.