Microstructure and Electrochemical Behavior of Sm_0.5Sr_0.5CoO₃ Deposited by Solution Precursor Plasma Spraying

Solution precursor plasma spraying (SPPS) was employed to prepare porous Sm_0.5Sr_0.5CoO₃ (SSC) cathode for solid oxide fuel cell (SOFC). The surface and cross-sectional morphology of the SSC deposit were characterized by scanning electron microscopy. The effect of annealing on SSPS SSC microstructure was examined. The electrochemical behavior was investigated through the impedance spectroscopy. The results showed that the SPPS SSC cathode deposited at a spray distance of 80 mm exhibits multidimensional porous microstructure. The porous film of the partially crystalline perovskite phase with a fine microstructure was obtained after annealing at 900 °C for 2 hours in air. The electrochemical measurement showed that the specific surface resistance of SSC decreased significantly with the increase of test temperature and yielded a specific surface resistance of 2.6 Ω·cm² at 800°C.