Electrochemical performances of nanocomposite solid oxide fuel cells using nano-size material LaNi _0.2Fe _0.65Cu _0.15O ₃ as cathode

In order to develop nanocomposite solid oxide fuel cells (NANOCOFCs) at the range of intermediate temperature (500-700 °C), the new cathode materials LaNi _0.2Fe _0.8-xCu _xO ₃ (x = 0.0-0.2) (LNFCu) powders were prepared using coprecipitation method. It was found that the orthorhombic structure could be formed after being calcined at 900 °C for 4 h, and the powders were mainly composed of nano-size particles. The lattice volume of LNFCu decreased with increasing x, and the second phase La ₂CuO ₄ appeared when x = 0.15. Fuel cells based on the nano-ceramic composite electrolyte were fabricated to evaluate the electrochemical properties of the LNFCu materials as cathodes at different operating temperatures. The peak power density of the fuel cell with LaFe _0.65Ni _0.2Cu _0.15O ₃ cathode reached 635.2 mW/cm ² and 762.7 mW/cm ² at 580 °C and 650 °C respectively, which were much higher than that of LaFe _0.8Ni _0.2O ₃ under the same condition. The results indicate doping with copper improves evidently electrochemical properties of the cathode compared with the LaFe _0.8Ni _0.2O ₃ cathode. The excellent performance of fuel cells makes LaNi _0.2Fe _0.8-xCu _xO ₃ material as the candidate electrode for NANOCOFCs.