Symmetrical solid oxide fuel cells with impregnated SrFe0.75Mo0.25O3-δ electrodes

Here we report nominally symmetrical solid oxide fuel cells that feature thin La0.9Sr0.1Ga0.8Mg0.2O3-delta (LSGM) electrolytes and impregnated SrFe0.75Mo0.25O3-delta (SFMO)-LSGM composite electrodes. Operation on hydrogen fuels and air oxidants can produce maximum power densities of 0.39 W cm(-2) at 650 degrees C and 0.97 W cm(-2) at 800 degrees C. Impedance measurements indicate that the anode and the cathode polarizations are 0.22 and 0.04 Omega cm(2) at 800 degrees C, respectively. Hydrogen partial pressure and temperature dependence of impedance data in humidified hydrogen shows that hydrogen oxidation kinetics is largely determined by hydrogen adsorption on the SFMO catalysts at high temperatures and charge transfer reactions along the SFMOILSGM interfaces at low temperatures. Carbon tolerance of the present fuel cells is also examined in iso-octane fuels balanced by nitrogen at 800 degrees C that yields stable maximum power densities of 0.39 W cm(-2). (C) 2013 Elsevier B.V. All rights reserved.