Oxygen transport in La0.6Sr0.4Co0.2Fe0.8O3-δ/Ce0.8Ge0.2O2-x composite cathode for IT-SOFCs

被引：124

作者：

Esquirol, A ^{[1
]}

Kilner, J ^{[1
]}

Brandon, N ^{[1
]}

机构：

[1] Univ London Imperial Coll Sci Technol & Med, Ctr Ion Conducting Membranes, London SW7 2AZ, England

来源：

SOLID STATE IONICS | 2004年 / 175卷 / 1-4期

关键词：

oxygen diffusion; surface exchange; IT-SOFC cathodes; impedance spectroscopy; composite cathode;

D O I：

10.1016/j.ssi.2004.09.013

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：

The oxygen transport properties and the performance of the composite La(0.6)r(0.4)CO(0.2)Fe(0.8)O(3)-sigma/Ce0.8Ge0.2O2-x, a potential IT-SOFC cathode material, were investigated. Using the isotopic exchange depth profiling (IEDP) technique with secondary ion mass spectroscopy (SIMS), the oxygen tracer diffusion coefficient, D* and the surface exchange coefficient k were measured. The measured D* values of the composite material were higher than that of the non-composite LSCF diffusion coefficient values, while the k values were similar to the noncomposite material at all temperatures. The area-specific resistance of the porous composite cathode was measured by impedance spectroscopy. A performance improvement was observed below 650 degreesC when compared to a non-composite LSCF cathode. This improvement was mainly attributed to the improvement in the oxygen tracer diffusion coefficient of the LSCF/CGO composite.

引用

页码：63 / 67

页数：5

共 15 条

[1] Electrode kinetics of porous mixed-conducting oxygen electrodes [J].

Adler, SB ;

Lane, JA ;

Steele, BCH .

JOURNAL OF THE ELECTROCHEMICAL SOCIETY, 1996, 143 (11) :3554-3564

[2]

ADLERSB, 1997, 3 INT S ION MIX COND, P539

[3] Oxygen diffusion and surface exchange in La0.8Sr0.2Fe0.8Cr0.2O3-δ under reducing conditions [J].

Atkinson, A ;

Chater, RJ ;

Rudkin, R .

SOLID STATE IONICS, 2001, 139 (3-4) :233-240

[4]

ATKINSON T, 2003, 1 INT C FUEL CELL SC

[5]

Benson S.J., 1999, THESIS IMPERIAL COLL

[6]

Crank J., 1979, MATH DIFFUSION

[7] Electrochemical reduction of oxygen on a strontium doped lanthanum manganite electrode [J].

Jiang, Y ;

Wang, SZ ;

Zhang, YH ;

Yan, JW ;

Li, WZ .

SOLID STATE IONICS, 1998, 110 (1-2) :111-119

[8]

KILNER JA, 1996, P 17 RIS INT S MAT S, P41

[9] Cathode materials for intermediate temperature SOFCs [J].

Maguire, E ;

Gharbage, B ;

Marques, FMB ;

Labrincha, JA .

SOLID STATE IONICS, 2000, 127 (3-4) :329-335

[10] Oxygen self-diffusion and surface exchange studies of oxide electrolytes having the fluorite structure [J].

Manning, PS ;

Sirman, JD ;

Kilner, JA .

SOLID STATE IONICS, 1996, 93 (1-2) :125-132

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