Increasing Power Density of LSGM-Based Solid Oxide Fuel Cells Using New Anode Materials

Abstract
Chemical reactions between the superior perovskite oxide-ion conductor Sr- and Mg-doped LaGaO3LaGaO3 (LSGM), CeO2,CeO2, and NiO have been studied by powder X-ray diffraction. The results showed that an extensive reactivity occurs as a result of La migration driven by a gradient of La chemical activity. La migration across the LSGM/electrode interfaces in a fuel cell leads to the formation of resistive phases at the interface, either LaSrGa3O7LaSrGa3O7 or LaSrGaO4.LaSrGaO4. Use of 40 mol % La2O3La2O3 -doped CeO2CeO2 as an interlayer between anode and electrolyte as well as in the NiO-containing anode prevents all reactions found. Consequently, the air- H2H2 cell maximum power density was increased to nearly 900 mW/cm2 at 800°C with a 600 μm thick LSGM electrolyte. No sign of degradation was observed at 800°C over 2 weeks for an interlayered cell under a loading current density of 250 mA/cm2. © 2001 The Electrochemical Society. All rights reserved.