Preparation and Electrochemical Properties of Cathode Materials Ln Y CuO for Solid Oxide Fuel Cell.

Ln Y CuO (Ln = Pr, Nd, Sm; = 0, 0.025, 0.05, 0.1) cathode materials were synthesized using a sol-gel method and calcination at 1000 °C for 24 h. The phase structure, coefficient of thermal expansion (CTE), electrical conductivity, and electrochemical impedance of cathode materials were characterized. X-ray diffraction (XRD) patterns show that the cell volume of each cathode material decreases with the increase in the Y doping amount and has good chemical compatibility with the SmCeO electrolyte. The thermal expansion test shows that the increase in Y doping reduces the average CTE of LnCuO. The conductivity test shows that Y doping increases the conductivity of LnCuO, and PrYCuO has the highest conductivity of 256 S·cm at 800 °C. The AC impedance test shows that Y doping reduces the polarization impedance of LnCuO, and PrYCuO has a minimum area-specific resistance (ASR) of 0.204 Ω·cm at 800 °C. In conclusion, PrYCuO has the best performance and is more suitable as a cathode material for a solid oxide fuel cell (SOFC).