Electrochemical performances of nanocomposite solid oxide fuel cells using nano-size material LaNi0.2Fe0.65Cu0.15O3...

In order to develop nanocomposite solid oxide fuel cells (NANOCOFCs) at the range of intermediate temperature (500-700 degrees C), the new cathode materials LaNi0.2Fe0.8-xCuxO3 (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 degrees 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 La2CuO4 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 LaFe0.65Ni0.2Cu0.15O3 cathode reached 635.2 mW/cm2 and 762.7 mW/cm2 at 580 degrees C and 650 degrees C respectively, which were much higher than that of LaFe0.8Ni0.2O3 under the same condition. The results indicate doping with copper improves evidently electrochemical properties of the cathode compared with the LaFe0.8Ni0.2O3 cathode. The excellent performance of fuel cells makes LaNi0.2Fe0.8-xCuxO3 material as the candidate electrode for NANOCOFCs.