화학공학소재연구정보센터
International Journal of Hydrogen Energy, Vol.37, No.15, 11345-11350, 2012
Synthesis and characterization of aluminum-doped perovskites as cathode materials for intermediate temperature solid oxide fuel cells
(Ba0.5Sr0.5)(Fe1-xAlx)O3-delta (BSFAx, x = 0-0.2) oxides have been synthesized as novel cobalt-free cathode materials for intermediate temperature solid oxide fuel cells (IT-SOFCs) using a sol-gel method. The BSFAx (x = 0-0.2) materials have been characterized by X-ray diffraction and scanning electron microscopy. The electrical conductivities and electrochemical properties of the prepared samples have also been measured. At 800 degrees C, the conductivity drops from 15 S cm(-1) to 5 S cm(-1) when the doping level of aluminum is increased to 20%. The aluminum-doping concentration has important impacts on the electrochemical properties of BSFAx materials. The BSFA0.09 cathode shows a significantly lower polarization resistance (0.26 Omega cm(2)) and cathodic overpotential value (55 mV at the current density of 0.1 A cm(-2)) at 800 degrees C. Furthermore, an anode-supported single cell with BSFA0.09 cathode has been fabricated and operated at a temperature range from 650 to 800 degrees C with humidified hydrogen (similar to 3vol% H2O) as the fuel and the static air as the oxidant. A maximum power density of 676 mWcm(-2) has been achieved at 800 degrees C for the single cell. We believe that BSFA0.09 is a promising cathode material for future IT-SOFCs application. Copyright (C) 2012, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved.