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Indexed by:期刊论文

Date of Publication:2014-12-25

Journal:JOURNAL OF POWER SOURCES

Included Journals:SCIE、Scopus

Volume:272

Page Number:371-377

ISSN No.:0378-7753

Key Words:Layered perovskite oxide; Pr3+-deficiency; Chemical defects; Electrical conductivity; Electrochemical performance

Abstract:Double-layered perovskite oxides of Pr1-yBaCo2O5+delta (P1-yBCO) with A-site Pr3+-deficiency contents of y = 0.00-0.10 have been studied with respect to phase structures, oxygen content, high-temperature chemical stabilities as well as electrical and electrochemical properties as cathode materials of intermediate-temperature solid oxide fuel cells (IT-SOFCs). The Pr3+-deficiency content in P1-yBCO is limited by similar to 8 mol%, and the Pr3+-deficiency hardly changes lattice parameters of P1-yBCO. Content of oxygen vacancies increases while that of Co4+ decreases with the higher Pr3+-deficiency content. P1-yBCO is chemically stable with the Gd0.1Ce0.9O1.95 (GDC) electrolyte at 1100 degrees C and below in air. Introduction of Pr3+-deficiency decreases electrical conductivities and significantly improves electrochemical performance of P1-yBCO. Among the studied oxides, P0.95BCO with 5 mol% Pr3+-deficiency shows the best electrochemical performance with low ASR values of 0.113 Omega cm(2) at 600 degrees C, 0.054 Omega cm(2) at 650 degrees C and 0.028 Omega cm(2) at 700 degrees C respectively, demonstrating it a promising cathode material of IT-SOFCs. The results of P1-yBCO have also been compared with those of Ba2+-deficient PrBa1-xCO2O5+delta (PB1-xCO, x = 0.00-0.10) oxides and major differences have been found in lattice parameters, oxygen content, chemical defects, electrical conductivities and ASR results. Factors contributing to these differences have been discussed. (C) 2014 Elsevier B.V. All rights reserved.