Optimizing the Copper Content in GdBa0.5Sr0.5Co2-XCuxO5+δDouble Perovskites as the High Performance Oxygen Electrodes for Reversible Solid Oxide Cells

Doping with copper is studied in a series of double perovskite-type GdBa0.5Sr0.5Co2-xCuxO5+δ, candidate oxygen electrode materials for reversible Solid Oxide Cells. Obtained by a sol-gel method, the material with x= 1.15, having the highest amount of the introduced Cu (lowest Co content) is selected, and systematically evaluated regarding physicochemical characteristics, as well as chemical stability with La0.8Sr0.2Ga0.8Mg0.2O3-δand Ce0.9Gd0.1O2-δsolid electrolytes. Promising electrochemical performance is obtained if this compound is used to manufacture oxygen electrodes, with the recorded low polarization resistance of 0.144 Ω cm2at 700 °C, and 0.020 Ω cm2at 850 °C. Also, the anode-supported laboratory cell is found to deliver over 725 mW cm-2power density at 850 °C, and shows good performance in the electrolyzer mode.