Electrochemically driven cation segregation in the mixed conductor La0.6Sr0.4Co0.2Fe0.8O3-δ

被引：54

作者：

Finsterbusch, M. ^{[1
,2
]}

Lussier, A. ^{[1
]}

Schaefer, J. A. ^{[2
]}

Idzerda, Y. U. ^{[1
]}

机构：

[1] Montana State Univ, Dept Phys, Bozeman, MT 59717 USA

[2] Ilmenau Univ Technol, Inst Phys, D-98684 Ilmenau, Germany

来源：

SOLID STATE IONICS | 2012年 / 212卷

关键词：

Fuel cell; MIEC; LSCF; Strontium; Segregation; X-ray absorption; OXIDE FUEL-CELL; TRANSPORT; ELECTRODE; CATHODES;

D O I：

10.1016/j.ssi.2012.02.006

中图分类号：

O64 [物理化学（理论化学）、化学物理学];

学科分类号：

070304 ; 081704 ;

摘要：

Strontium segregation as function of electrochemical environment is measured for La0.6Sr0.4Co0.2Fe0.8O3 - delta using X-ray absorption spectroscopy. Gaseous Cr is used as a tracer to distinguish the bulk Sr from the segregated SrO at the surface via formation of SrCrO4. From the SrCrO4 to Cr2O3 ratio, the impact of cathodic and anodic overpotentials on Sr segregation is determined. While low anodic overpotentials were found to inhibit Sr segregation, higher overpotentials promote increased Sr segregation at the anode compared to the cathode. Oxygen vacancy concentration variations, caused by the overpotentials existing during operation, are identified as the driving mechanism for the Sr out-diffusion. Using this proposed Sr segregation mechanism, possible mitigation strategies are suggested. (C) 2012 Elsevier B.V. All rights reserved.

引用

页码：77 / 80

页数：4

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