Remarkable dependence of electrochemical performance of SrCo0.8Fe0.2O3-delta on A-site nonstoichiometry

	Remarkable dependence of electrochemical performance of SrCo0.8Fe0.2O3-delta on A-site nonstoichiometry
	Liu, Huanying 1,2; Zhu, Xuefeng 1; Cong, You 1; Zhang, Tianyu 1; Yang, Weishen 1
刊名	physical chemistry chemical physics
	2012
卷号	14 期号:20 页码:7234-7239
英文摘要	srco0.8fe0.2o3-delta is a controversial material whether it is used as an oxygen permeable membrane or as a cathode of solid oxide fuel cells. in this paper, carefully synthesized powders of perovskite-type srxco0.8fe0.2o3-delta (x = 0.80-1.20) oxides are utilized to investigate the effect of a-site nonstoichiometry on their electrochemical performance. the electrical conductivity, sintering property and stability in ambient air of srxco0.8fe0.2o3-delta are critically dependent on the a-site nonstoichiometry. sr1.00co0.8fe0.2o3-delta has a single-phase cubic perovskite structure, but a cobalt-iron oxide impurity appears in a-site cation deficient samples and sr-3(co, fe)(2)o7-delta appears when there is an a-site cation excess. it was found that the presence of the cobalt-iron oxide improves the electrochemical performance. however, sr-3(co, fe)(2)o7-delta has a significant negative influence on the electrochemical activity for intermediate-temperature solid oxide fuel cells (it-sofcs). the peak power densities with a single-layer sr1.00co0.8fe0.2o3-delta cathode are 275, 475, 749 and 962 mw cm(-2) at 550, 600, 650 and 700 degrees c, respectively, values which are slightly lower than those for sr0.95co0.8fe0.2o3-delta (e.g. 1025 mw cm(-2) at 700 degrees c) but much higher than those for sr1.05co0.8fe0.2o3-delta (e.g. only 371 mw cm(-2) at 700 degrees c). this remarkable dependence of electrochemical performance of the srxco0.8fe0.2o3-delta cathode on the a-site nonstoichiometry reveals that lower values of electrochemical activity reported in the literature may be induced by an a-site cation excess. therefore, to obtain a high performance of srxco0.8fe0.2o3-delta cathode for it-sofcs, an a-site cation excess must be avoided.
WOS标题词	science & technology ; physical sciences
类目[WOS]	chemistry, physical ; physics, atomic, molecular & chemical
研究领域[WOS]	chemistry ; physics
关键词[WOS]	oxide fuel-cells ; intermediate temperature sofcs ; anode materials ; composite cathodes ; oxygen permeation ; electrical-conductivity ; power-density ; it-sofc ; perovskites ; electrolyte
收录类别	SCI
语种	英语
WOS记录号	WOS:000303444000006
公开日期	2015-11-10
内容类型	期刊论文
源URL	[http://159.226.238.44/handle/321008/138096]
专题	大连化学物理研究所_中国科学院大连化学物理研究所
作者单位	1.Chinese Acad Sci, State Key Lab Catalysis, Dalian Inst Chem Phys, Dalian 116023, Peoples R China 2.Chinese Acad Sci, Grad Sch, Beijing 100039, Peoples R China
推荐引用方式 GB/T 7714	Liu, Huanying,Zhu, Xuefeng,Cong, You,et al. Remarkable dependence of electrochemical performance of SrCo0.8Fe0.2O3-delta on A-site nonstoichiometry[J]. physical chemistry chemical physics,2012,14(20):7234-7239.
APA	Liu, Huanying,Zhu, Xuefeng,Cong, You,Zhang, Tianyu,&Yang, Weishen.(2012).Remarkable dependence of electrochemical performance of SrCo0.8Fe0.2O3-delta on A-site nonstoichiometry.physical chemistry chemical physics,14(20),7234-7239.
MLA	Liu, Huanying,et al."Remarkable dependence of electrochemical performance of SrCo0.8Fe0.2O3-delta on A-site nonstoichiometry".physical chemistry chemical physics 14.20(2012):7234-7239.