Electrochemical properties of GdBaCo2/3Fe2/3Cu2/3O5+delta-CGO composite cathodes for solid oxide fuel cell

Abstract

The composite cathodes of double-perovskite structure of xwt.% Ce0.9Gd0.1O1.95 (CGO)-(100 - x)wt.% GdBaCo2/3Fe2/3Cu2/3O5+delta (FC-GBCO), where x = 0, 10, 20, 40 and 50, were synthesized via a citrate combustion method followed by an organic precipitant method. The thermal-expansion coefficient (TEC) and electrochemical performance of the oxides were investigated as potential cathode materials for intermediate-temperature solid oxide fuel cells (IT-SOFCs). The TEC exhibited by composite cathode made of 40 wt.% CGO-60 wt.% FC-GBCO (CG40) up to 900 degrees C is 13.7 x 10(-6)degrees C-1, which is lower value than FC-GBCO (16.3 x 10(-6)degrees C-1). The composite cathode of CG40 coated on Ce0.9Gd0.1O1.95 electrolyte showed the lowest area specific resistance (ASR) i.e., 0.041 Omega(2), cm(2) at 750 degrees C. An electrolyte supported (300 mu m thick) single-cell configuration of CG40/CGO/Ni-CGO attained a maximum power density of 800 mW cm(-2) at 800 degrees C. The unique composite composition of CG40 exhibited enhanced electrochemical performance, reduced TEC and good chemical compatibility with COO electrolyte compared with their FC-GBCO cathode for IT-SOFCs. (C) 2011 Elsevier Ltd and Techna Group S.r.l. All rights reserved.