Characterization of the microstructure and electrochemical behavior of Sm0.7Sr0.3Co3−δ cathode deposited by solution precursor plasma spraying

Mixed conducting strontium doped samarium cobaltite perovskites as cathodes in solid oxide fuel cell (SOFC) have received much attention due to their low polarization at low operating temperature. On the other hand, thermal spraying is considered to be a promising cost-effective processing method because of its fast deposition feature compared with other film formation processes. Moreover, the functional layers in nanometer and sub-micrometer size grains can be easily deposited by solution precursor plasma spraying (SPPS). In this work, strontium doped samarium cobaltite (Sm0.7Sr0.3CoO3−δ, SSC) cathodes were deposited by SPPS to aim to reducing the polarization. The deposit phase structure was characterized by x-ray diffraction, and the surface morphology was examined by scanning electron microscopy. The electrochemical behavior of SPPS-sprayed SSC cathodes was investigated through the impedance spectroscopy. The effect of spray distance on the polarization was discussed.