Ferrite-based cathodes

Wang WG and Mogensen M. High-performance lanthanum-ferrite-based cathode for SOFC. Solid State Ionics 2005 176 457 -62. 

Simner, S.P., Bonnett, J.F., Canfield, N.L., Meinhardt, K.D., Sprenkle, V.L., and Stevenson, J.W., Optimized lanthanum ferrite-based cathodes for anode-supported SOFCs, Electrochemical Solid-State Letters, 2002, 5, A173. 

C., Mertens, J., and Tietz, F. (2010) Various lanthanum ferrite-based cathode materials with Ni and Cu substitution for anode-supported solid oxide fuel cells. J. Fuel Cell Sci. Technd., 7, 061017-1-061017-4. 

Mai A, HaanappelVAC, UhlenbruckS, TietzF, and Stover D. Ferrite-based perovskites as cathode materials for anode-supported solid oxide fuel cells, Part I. Variation of composition. Solid State Ionics 2006 176 1341-1350. 

In this chapter the technological development in cathode materials, particularly the advances being made in the material s composition, fabrication, microstructure optimization, electrocatalytic activity, and stability of perovskite-based cathodes will be reviewed. The emphasis will be on the defect structure, conductivity, thermal expansion coefficient, and electrocatalytic activity of the extensively studied man-ganite-, cobaltite-, and ferrite-based perovskites. Alterative mixed ionic and electronic conducting perovskite-related oxides are discussed in relation to their potential application as cathodes for ITSOFCs. The interfacial reaction and compatibility of the perovskite-based cathode materials with electrolyte and metallic interconnect is also examined. Finally the degradation and performance stability of cathodes under SOFC operating conditions are described. 

The current state-of-the-art SOFC anode-supported cells based on doped zircona ceramic electrolytes, ceramic LSM cathodes, and Ni/YSZ cermet anodes are operated in the temperature range 700-800°C with a cell area specific resistance (ASR) of about 0.5 O/cm at 750°C. Using the more active ceramic lanthanum strontium cobalt ferrite (LSFC)-based cathodes, the ASR is decreased to about 0.25 Q/cm at this temperature, which is a more favorable value regarding overall stack power density and cost-effectiveness. 

Hydrogen embrittlement can occur in carbon and low-alloy steels, in ferritic and martensitic stainless steels, and in duplex stainless steels. It is normally not a problem in either the austenitic stainless steels or nickel-based high alloys. Hydrogen can dissolve in a steel as a result of a number of phenomena (1) Corrosion creates nascent hydrogen, usually in the presence of a cathodic poison. 

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