A-site Ba-deficiency layered perovskite EuBa1-xCO2O6-delta cathodes for intermediate-temperature solid oxide fuel cells: Electrochemical properties and oxygen reduction reaction kinetics

作者：Li, Shuli; Xia, Tian^*; Li, Qiang; Sun, Liping; Huo, Lihua; Zhao, Hui^*

来源：International Journal of Hydrogen Energy, 2017, 42(38): 24412-24425.

DOI：10.1016/j.ijhydene.2017.08.049

• Intermediate-temperature solid oxide fuel cells
• Cathode materials
• Layered perovskite
• Electrochemical properties
• Oxygen reduction reaction

A-site Ba-deficiency layered perovskite oxides, EuBa1-xCO2O6-delta (EB1-x CO, x = 0.02 and 0.04), have been synthesized by a citric acid-ethylene diamine tetraacetic acid complexation sol-gel method, and evaluated as potential cathode materials for intermediate-temperature solid oxide fuel cells (IT-SOFCs). Room temperature powder X-ray diffraction patterns indicate that the EB1-xCO oxides crystallize in an orthorhombic symmetry with space group Pmmm. Among all of components, EB0.98CO exhibits a good chemical compatibility with Ce0.9Gd0.1O1.95 (CGO) electrolyte, as evidenced by phase analysis of mixed EB0.98CO-CGO after calcining at 950 degrees C for 12 h in air. Thermal expansion analysis gives an average thermal expansion coefficient of 16.7 x 10(-6) K-1. for EB0.98CO. Thermogravimetric measurement confirms the high oxygen nonstoichiometric characteristic of EB0.98CO at elevated temperatures. The electrical conductivity values of EB0.98CO exceed 300 S cm(-1) in the temperature range of 100-750 degrees C. When tested as cathode in IT-SOFCs, the polarization resistance of 0.107 Omega cm(2) and the overpotential of 10 mV at current density of 77 mA cm(-2) are achieved in the EB0.98CO cathode at 700 degrees C in air. The EB0.98CO cathode-based anode-supported single cell delivers the maximum power density of 505 mW cm(-2) at 700 degrees C. Finally the rate-limiting steps for oxygen reduction reaction at the EB0.98CO cathode interface are determined to be the charge transfer reaction and gas-phase diffusion process. 2017 Hydrogen Energy Publications LLC. Published by Elsevier Ltd.

• 出版日期2017-9-21
• 单位黑龙江大学