Evaluation of double perovskite Sr2FeTiO6-δ as potential cathode or anode materials for intermediate-temperature solid oxide fuel cells

A cobalt-free double perovskite electrode material with stoichiometric composition Sr2FeTiO6-delta (SFT) has been developed for intermediate-temperature solid oxide fuel cells (IT-SOFCs) using Ce0.8Sm0.2O1.9 (SDC) electrolyte. The reactivity tests show that the SFT electrode is chemically compatible with the SDC electrolyte at 1100 degrees C for 10 h. The electrical conductivity of SFT sample reaches 2.83-2.33 S cm(-1) the temperature range of 600-800 degrees C. The thermal expansion coefficient of the SFT sample is 16.8 x 10(-6) K-1 the temperature range of 30 1000 degrees C in air, which is lower than that of most of the reported Co-based electrodes. Using NiO-SDC as anode, SFT as cathode, and SDC as supported electrolyte, the single cell exhibits maximum power density of 441 mW cm(-2) at 800 degrees C. The area specific resistances of the SFT electrode on SDC electrolyte calcined at 1000 degrees C were found to be 0.051, 0.094 and 0.204 Omega cm(2) at 800, 750 and 700 degrees C, respectively. Maximum power density of 335 mW cm(-2) has been achieved for a symmetrical single cell with the configuration of SFT/SDC/SFT at 800 degrees C with wet H-2 as fuel and ambient air as oxidant. These results indicate that SFT is a very promising electrode candidate for IT-SOFCs with SDC electrolyte. (C) 2015 Elsevier Ltd and Techna Group S.r.l. All rights reserved.