Structural, chemical, and electrochemical characteristics of LaSr ₂Fe ₂CrO _9-δ-based solid oxide fuel cell anodes

Solid oxide fuel cells with LaSr ₂Fe ₂CrO _9-δ-Gd _0.1Ce _0.9O _2-δ composite anodes were tested in H ₂, H ₂S-contaminated H ₂, and CH ₄ fuels as well as under redox cycling conditions. The La _0.9Sr _0.1Ga _0.8Mg _0.2O _3-δ electrolyte supported cells had La _0.4Ce _0.6O _2-δ barrier layers to prevent cation diffusion between LaSr ₂Fe ₂CrO _9-δ and La _0.9Sr _0.1Ga _0.8Mg _0.2O _3-δ. After an initial break-in where the performance improved slightly, the cells were stable in humidified H ₂ with a power density > 0.4 W cm ^{- 2} and an anode polarization resistance as low as 0.22 Ω cm ². Anode polarization resistance showed little or no change after 15 redox cycles at 800 °C. Cell performance was stable with 22 ppm H ₂S, with only a slight performance decrease relative to pure H ₂, but higher H ₂S concentrations caused continuous degradation. Also, the performance in humidified CH ₄ fuel was quite low.