Optimized energy conversion efficiency in solid-oxide fuel cells implementing SrMo1-xFexO3-δ perovskites as anodes

Oxides of composition SrMo1-xFexO3-delta (x=0.1, 0.2) have been prepared, characterized and tested as anode materials in single solid-oxide fuel cells, yielding output powers close to 900 mW cm(-2) at 850 degrees C with pure H-2 as a fuel. This excellent performance is accounted for the results of an in situ neutron powder diffraction experiment, at the working temperature of the SOFC, showing the presence of a sufficiently high oxygen deficiency, with large displacement factors for oxygen atoms that suggest a large lability and mobility, combined with a huge metal-like electronic conductivity, as high as 340S cm(-1) at T=50 degrees C for x=0.1. The magnitude of the electronic conductivity decreases with increasing Fe-doping content. An adequate thermal expansion coefficient, reversibility upon cycling in oxidizing-reducing atmospheres and chemical compatibility with the electrolyte make these oxides good candidates for anodes in intermediate-temperature SOFC (IT-SOFCs). (C) 2012 Elsevier B.V. All rights reserved.