A novel post-treatment to calcium cobaltite cathode for solid oxide fuel cells

The calcium cobaltite (CCO) cathodes are post-treated by dipping in the hydrogen peroxide (H₂O₂). The electrochemical properties are investigated by the electrochemical impedance spectra (EIS) and current-voltage test in the symmetrical cell and single cell, respectively. The phase structure and morphology of the cathodes are characterized by X-ray powder diffraction (XRD) and scanning electron microscopy (SEM). The experiment results show that the mesopores are created on the surface of the cathode particles and the pore channels of the cathode are cleaned up after leaching with 10 wt % H₂O₂, resulting in a remarkable decreasing of the area specific resistance (e.g. only 42.5% of that for the untreated cathode at 800 °C). The single cell with treated cathode is about 2 times the peak power density of the cell with untreated cathode, signifying the post-treating method may be promising.