Title of article
Electrochemically driven cation segregation in the mixed conductor La0.6Sr0.4Co0.2Fe0.8O3 − δ
Author/Authors
Finsterbusch، نويسنده , , M. and Lussier، نويسنده , , A. and Schaefer، نويسنده , , J.A. and Idzerda، نويسنده , , Y.U.، نويسنده ,
Issue Information
هفته نامه با شماره پیاپی سال 2012
Pages
4
From page
77
To page
80
Abstract
Strontium segregation as function of electrochemical environment is measured for La0.6Sr0.4Co0.2Fe0.8O3 − δ 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.
Keywords
MIEC , Segregation , LSCF , strontium , Fuel cell , X-ray Absorption
Journal title
Solid State Ionics
Serial Year
2012
Journal title
Solid State Ionics
Record number
1711336
Link To Document