Solid State Ionics, Vol.326, 116-123, 2018
Study of La4BaCu5-xCoxO13+delta series as potential cathode materials for intermediate-temperature solid oxide fuel cell
La4BaCu5-xCoxO13+delta system was successfully synthesized by a modified Pechini route in air. A structural phase transition is observed along the series, from tetragonal ordered structure for 0 <= x <= 2 to a rhombohedral disordered perovskite for x = 5. A TEC value of 17.3 x 10(-6) K-1, was found by High-Temperature X-ray Diffraction (HT-XRD) in air for La4BaCu5-xCoxO13+delta. The conductivity of La4BaCu5-xCoxO13+delta increases with temperature reaching a maximum of 778 S cm(-1) at 405 degrees C in air followed by a decrease with further increase in temperature with values of 600-664 S cm(-1). The cathode polarization resistance of La4BaCu5-xCoxO13+delta evaluated in air at 750 degrees C is 0.34 Omega cm(2) with an activation energy of 1.65 eV. These results demonstrate the possible use of La4BaCu5-xCoxO13+delta materials as cathode for Intermediate-Temperature Solid Oxide Fuel Cell (IT-SOFC).
Keywords:SOFC;Perovskite;Cathode;Cobaltocuprate;Electrical conductivity;Electrochemical impedance spectroscopy