Material Characteristics and Electrochemical Performance of YxBa2-XCo2O5+δ Cathode for Solid Oxide Fuel Cell

Monday, 27 July 2015
Hall 2 (Scottish Exhibition and Conference Centre)
I. M. Hung, J. A. Wang (Dep. of Chem. Eng. and Mater. Sci., Yuan Ze University), J. Y. Kuo (Atomic Energy Council), and T. N. Lin (Chem. Eng. Division, Institute of Nuclear Energy Research)
A new YxBa2-xCo2O5+δ cathodes were successfully prepared by solid-state reaction method. The structure, microstructure, conductivity, coefficient of thermal expansion and electrochemical properties of these YxBa2-xCo2O5+δ cathodes were conducted by XRD, SEM, 4 DC four-terminal method, thermomechanical analysis and AC impedance, respectively. The YBaCo2O5+δ is a single phase with double perovskite structure. The second phases of YBa2Co3O9-δ and Y2O3 were observed as the x>1 and x<1, respectively. The conductivity of all YxBa2-xCo2O5+δ amples increased as temperature increased, and show a p-type conductor characterization. The YBaCo2O5+δ exhibited a maximum conductivity of 256 S/cm at 300 oC. The coefficient of thermal expansion is 13.8*10-6, which is close to that of Samaria-doped Ceria (SDC) electrolyte. The YBaCo2O5+δdid not react with SDC electrolyte below 1050 oC. The YBaCo2O5+δ is a potential cathode material for intermediate temperature solid oxide fuel cell.