Abstract
Mixed rare-earth (La, Pr)(0.8)Sr0.2FeO3-delta-Sm0.2Ce0.8O2-delta (LPSF-SDC) composite cathode was investigated for proton-conducting solid oxide fuel cells based on protonic BaZr0.1Ce0.7Y0.2O3-delta (BZCY) electrolyte. The powders of La0.8-xPrxSr0.2FeO3-delta (x = 0, 0.2, 0.4, 0.6), Sm0.2Ce0.8O2-delta,(SDC) and BaZr0.1Ce0.7Y0.2O3-delta (BZCY) were synthesized by a citric acid-nitrates self-propagating combustion method. The XRD results indicate that La0.8-xPrxSr0.2FeO3-delta samples calcined at 950 degrees C exhibit perovskite structure and there are no interactions between LPSF0.2 and SDC at 1100 C. The average thermal expansion coefficient (TEC) of LPSF0.2-SDC, BZCY and NiO-BZCY is 12.50 x 10(-6) K-1, 13.51 x 10(-6) K-1 and 13.47 x 10(-6) K-1, respectively, which can provide good thermal compatibility between electrodes and electrolyte. An anode-supported single cell of NiO-BZCY vertical bar BZCY vertical bar LPSF0.2-SDC was successfully fabricated and operated from 700 degrees C to 550 degrees C with humidified hydrogen (similar to 3% H2O) as fuel and the static air as oxidant. A high maximum power density of 488 mW cm(-2), an open-circuit potential of 0.95 V, and a low electrode polarization resistance of 0.071 Omega cm(2) were achieved at 700 degrees C. Preliminary results demonstrate that LPSF0.2-SDC composite is a promising cathode material for proton-conducting solid oxide fuel cells. Copyright (C) 2014, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved.