Lanthanum based electrolytes doping

Lanthanum gallate is doped with divalent metal ions, for instance, strontium and magnesium Lai jSrjMgyGai j,03 usually, x and y have values between 1 and 0. Unlike the ceria-based electrolytes, this electrolyte can also be used at low oxygen partial pressures without the menace of developing an electronic conductivity. When in contact with cathodes of the LSM- or LSC type, some diffusion of manganese and cobalt from the cathode into the electrolyte is possible, but this has little effect on the fuel cell s performance. A certain defect of this electrolyte material is its complicated preparation procedure. 

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. 

This paper presents results of research aimed at development of efficient synthesis procedirres and characterization of oxide-ion conducting electrolytes based on doped lanthanum sihcate with the apatite stiuctirre promising for design of solid oxide fuel cells operating at intermediate temperatirres. Phase-pure nanocrystalline powders of doped... 

In this chapter, the key competences of our technology toward the development of commercial SOFC power generation units utilizing cation-doped lanthanum gallate-based electrolyte are summarized. 

For intermediate temperature SOFCs, a composite cathode consisting of strontium-doped lanthanum manganite (LSM) and YSZ has shown good performance [10]. For use with ceria-based electrolytes [11], a (La,Sr)(Co,Fe)03 (LSCF)-based cathode has been developed [12],... 

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