Structural, Microstructural and Electrochemical Studies of Co/Mn Derived Oxides as Protective Layers for Intermediate Temperature SOFCs

Abstract

Abstract. Designing highly protective and superior electrically conductive coatings from Cobalt-manganese doped/un-doped oxide materials (CMOs) is the main target of this study. The as-prepared nanopowders were synthesized via glycine nitrate process (GNP) at moderate annealing temperature afterword characterized using several techniques including X-rays diffraction (XRD), Field emission scanning electron microscopy (FE-SEM) and electrochemical impedance measurements at room temperature. The XRD results revealed a pure phase of spinel structure with particle size range 75-81 nm for the doped CMO samples. SEM micrographs exhibited morphology with fine aggregate of particles. The incorporation of different ions of Cu, Ni, Fe and Na into the CMOs structure showed a significant increase in the diffusivity of ions and remarkable improvement in the crystallinity. AC electrical conductivity was also measured for the compacted pellets after sintering at 850°C using the electrochemical impedance spectroscopy technique at room temperature. From the obtained results it could be concluded that the polarization resistance of pure and modified CMOs samples show similar behavior ranged from 5 to 6 k Ω.