Thermal and electrochemical properties of layered perovskite PrBaCo2-xMnxO5+delta (x=0.1, 0.2 and 0.3) cathode materials for intermediate temperature solid oxide fuel cells

摘要

Layered perovskite PrBaCo2-xMnxO5+delta (PBCM-x, x = 0.1, 0.2 and 0.3) oxides have been synthesized and investigated as cathode materials for intermediate temperature solid oxide fuel cells (IT-SOCFs). The effects of Mn contents in PBCM-x materials on the crystal structure, chemical stability, thermal expansion coefficient (TEC) and electrochemical properties have been studied. XRD results have showed that the lattice parameters increase with x increasing from 0.1 to 0.3, although the crystalline structure does not change. The substitution of Co by Mn lowers the thermal expansion coefficient clearly. The average TEC decreases from 22.8 x 10(-6) K-1 for PBCM-1 to 15.1 x 10(-6) K-1 for PBCM-3 in the temperature range of 35-800 degrees C. The PBCM-x samples exhibit a semiconductor to metal transition. All the samples reach the general required electrical conductivity value of cathode material at the operating temperature range of 600-800 degrees C. Among the samples, PBCM-2 shows the best electrochemical performance. The single fuel cell with the configuration of PBCM-2/YSZ/Pt delivers the highest power density of 304.2 mW cm(-2) at 800 degrees C. Copyright (C) 2015, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved.