CYO-BZCYO composites with enhanced proton conductivity: Candidate electrolytes for low-temperature solid oxide fuel cells

Novel composite oxide ion conductors were developed based on a fluorite-type Ce0.8Y0.2O1.9 (CYO) and a perovsldte-type BaZr0.1Ce0.7Y0.2O2.9 (BZCYO) synthesized by the carbonate co-precipitation route at 700 degrees C and the sol-gel process at 1000 C, respectively. When sintered at 1400 degrees C, CYO and BZCYO showed an ac conductivity of 1.60 x 10(-2) S cm(-1) and 1.21 x 10(-2) S cm(-1) at 600 degrees C, respectively, in dry air and wet hydrogen. CYO-BZCYO composites sintered at 1400 degrees C showed much lower conductivity than CYO and BZCYO in dry air, but they showed enhanced conductivity in wet hydrogen. The highest conductivities of 3.27 x 10(-2) S cm(-1) at 500 degrees C and 9.40 x 10(-3) S cm(-1) at 400 degrees C were achieved in wet hydrogen by the composite containing 30wt.% BZCYO, which are 3-5 times higher than those of CYO and BZCYO, making this composite material a promising candidate as an electrolyte for low-temperature solid oxide fuel cells (LT-SOFCs). Copyright (C) 2012, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved