NdBaMn2O5+delta layered perovskite as an active cathode material for solid oxide fuel cells

A layered perovskite, NdBaMn2O5+delta (NBMO), was synthesized by solid state reaction method in air. Rietveld analysis of X-Ray Diffraction (XRD) data showed the material crystallizing in orthorhombic symmetry (Pmmm space group). Scanning electron microscopy (SEM) was used to check the morphology and, the analysis of the micrographs exhibited a porous structure with in-situ growth of nanoparticles. Electrochemical Impedance Spectroscopy (EIS) measurements from 600 degrees C to 800 degrees C shows the highest conductivity value of 1.17 x 10(-1) S/cm obtained at 800 degrees C with low activation energy (Ea) of 0.3 eV in air. In 5% H-2/Ar gas mixture, the conductivity and activation energy values were 1.97 x 10(-2) S/cm and 0.4 eV, respectively at 800 degrees C. The DC conductivity measurements also showed that this material is highly conductive in air with a conductivity value of 0.75 S/cm at 850 degrees C. Dual chamber fuel cell measurements on Ni-YSZ/YSZ/NBMO cell using 5% H-2/Ar as fuel (from 700 degrees C to 800 degrees C) showed a maximum power density of 0.202 W/cm(2) at 800 degrees C. The relatively high conductivity of the material in air and low activation energy makes it a potential candidate as cathode for solid oxide fuel cells.