The Characterization of Oxygen Deficit Cathode Sm0.5Sr0.5Co(subscript 1-x)Cu(subscript x)O(subscript 3-δ) (x=0~0.3) for Intermediate Temperature-Solid Oxide Fuel Cells (IT-SOFCs)

Abstract

The recent research of solid oxide fuel cells (SOFCs) is focus on reduces the operating temperature from high temperature to intermediate temperature. Sm0.5Sr0.5CoO(subscript 3-δ) (SSC) was a common mixed ionic and electronic conductor (MIEC) for IT-SOFCs cathode between 500~800℃ based on Samarium-doped ceria (SDC) electrolyte. In this study, new oxygen deficit cathode Copper-doped SSC, Sm0.5Sr0.5Co(subscript 1-x)Cu(subscript x) (X=0~0.3) (SSCC) was prepared by conventional solid state reaction. The structure characterization, thermal compatibility and the thermal expansion coefficients (TECs) were analyzed by X-ray diffraction (XRD) and Thermal mechanical analyzer (TMA). The ionic conductivity of SSCC was expected to be enhanced due to the measurement of ac impedance spectroscopy investigations revealed that an interfacial polarization resistance of Cu-doped SSC was lower than conventional SSC cathode. The electrical conductivity of SSCC decreased while Cu substituting for Co and the Sm0.5Sr0.5Co0.8Cu0.2O(subscript 3-δ) cathode exhibit the maximum conductivity that was 466 S/cm and 360 S/cm at 500℃ and 800℃. However, it was high enough to be IT-SOFCs cathode.