Lanthanum ferrite cathodes

Single-phase perovskite MIECs such as Sr-doped lanthanum cobaltite (LSC), lanthanum ferrite (LSF), lanthanum cobalt ferrite (LSCF) and samarium cobaltite (SSC), and Ca-doped lanthanum ferrite (LCF) [13] are sometimes used alone in SOFC cathodes, as depicted in the lower right-hand comer of Figure 6.1, but combining an... 

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. 

Adequate electronic and ionic conductivity. Though the conductivities are adequate, the ionic conductivity of LSM is significantly lower than YSZ, and its electronic conductivity is a fraction of any of the metals or even of lanthanum chromite. Consequently, ionic and electronic resistance can become a significant factor, especially in cell designs that incorporate long current paths through the cathode. For lower-temperature cells, conductivity of LSM is inadequate, and other materials, such as strontium-doped lanthanum ferrite (LSF) are considered. 

Simner SP, Bonnett JR, Canfield NL et al (2003) Development of lanthanum ferrite SOFC cathodes. J Power Sources 113 1-10... 

In many cases, achievement of reliability is in trade-off relation to cost reduction. To overcome this, it is required to make breakthroughs in the fabrication technologies. Cells to be operated in the temperature region of around 800°C. Metal intercoruiects are used together with anode-support cells and sealing materials. The active cathode such as LSCF (lanthanum strontium cobaltite ferrites) is used so that the durability is one of the main issues. 

Table 18.2 Comparison of cathodes among lanthanum strontium manganites, ferrites, and cobaltites in their chemical reactivity, functionality as cathode, and tolerance against Cr poisoning...

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. 

Strontium-doped lanthanum manganite, La1 3.Sr3.MnO3 (LSM) is developed by doping lanthanum manganite with a small fraction (10%-20%) of strontium in order to enhance electronic conductivity of the cathode electrode. Lanthanum strontium cobalt ferrite (LSCF) is a mixture of lanthanum oxide, strontium oxide, cobalt oxide, and iron oxide with typical composition given as Lao eSro iCoo Fco sOs. 

---