Characterization of Nanostructured NiDoped (Ce,Gd)O2D Anodes for IntermediateTemperature Solid Oxide Fuel Cells (ITSOFC)

FERNANDEZ ZUVICH, AFRA; SOLDATI, ANALIA L.; NAPOLITANO, FEDERICO; LARRONDO, SUSANA A.; SALETA, MARTÍN; LAMAS, DIEGO; CANEIRO, ALBERTO; SERQUIS, ADRIANA C.

San Diego

Congreso; ECS 229 - The Anual Meeting of the Electro-Chemical Society 2016; 2016

The Electrochemical Society

The development of IntermediateTemperature Solid Oxide Fuel Cells (ITSOFC)as high efficient energy conversion systems requires the optimization of its components: cathode, anode and electrolyte. CeO2based materials present excellent catalytic properties for the oxidation of H2 and CH4 fuels. Through the incorporation of metals oxides (Gd2O3, Sm2O3, Y2O3) in the CeO2 lattice the ionic conductivity can be significantly improved, becoming good electrolytes, particularly (Ce,Gd)O2d (CGO) compound. Furthermore, the addition of metals such as Ni or Cu enhances the material electronic conductivity, thus enabling them as efficient ITSOFCanodes [1].It is recognized that the polarization characteristics of NiCGO cermet anodes are strongly affected by their preparation conditions, which determine the microstructure and morphology of these materials. For that reason, further exploration of new microstructures has to be done in order to improve anode performance [2]. In a previous work we presented a new modified solgelmethod to incorporate Ni into the precursors solution, which produced a powder with a very homogeneous Ni distribution resulted in smaller particle sizes with narrower distribution than the commercial cermet [3]. In this work, we present a study of the performance of these anodes sintered at different temperatures for the hydrogen oxidation reaction. The electrode polarization resistance is evaluated through Electrochemical Impedance Spectroscopy (EIS) on symmetric cells, while the cell power of NiCGO/ CGO/LSCF configuration is measured in a homemadeequipment. The structural and morphological characterization are analyzed by XRay Diffraction and Transmission and Scanning Electron Microscopy, respectively. The study of the oxidation state and coordination of Ce and Ni in these cermets, simulating inoperando conditions, was performed using synchrotron Dispersive Xray absorption spectroscopy (DXAS) technique. The correlation between the electrochemical behavior, electronic properties and microstructural characteristics will be discussed.