Sr2Fe4/3Mo2/3O6 as anodes for solid oxide fuel cells

Sr2Fe4/3Mo2/3O6 has been synthesized by a combustion method in air. It shows a single cubic perovskite structure after being reduced in wet H2 at 800 °C and demonstrates a metallic conducting behavior in reducing atmospheres at mediate temperatures. Its conductivity value at 800 °C in wet H2 (3% H2O) is about 16 S cm−1. This material exhibits remarkable electrochemical activity and stability in H2. Without a ceria interlayer, maximum power density (Pmax) of 547 mW cm−2 is achieved at 800 °C with wet H2 (3% H2O) as fuel and ambient air as oxidant in the single cell with the configuration of Sr2Fe4/3Mo2/3O6|La0.8Sr0.2Ga0.83Mg0.17O3 (LSGM)| La0.6Sr0.4Co0.2Fe0.8O3 (LSCF). The Pmax even increases to 595 mW cm−2 when the cell is operated at a constant current load at 800 °C for additional 15 h. This anode material also shows carbon resistance and sulfur tolerance. The Pmax is about 130 mW cm−2 in wet CH4 (3% H2O) and 472 mW cm−2 in H2 with 100 ppm H2S. The cell performance can be effectively recovered after changing the fuel gas back to H2.