Lanthanum based electrolytes

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. 

T. Inagaki, F. Nishiwaki, S. Yamasaki, T. Akbay and K. Hosoi, Intermediate Temperature Solid Oxide Fuel Cell based on Lanthanum Gallate Electrolyte,/. Power Sources, 181,274-280(2008). 

However, in this fluorine sensor, the base electrolyte is composed of the lanthanum cation with the fluorine anion. In addition, one unusual property is that the sensor can operate even when directly immersed into aqueous solutions at room temperature. The realization of the application is greatly dependent on two facts Lap3 is stable in water and it shows an excellent fluorine conduction even at room temperature. These remarkable characteristics permit the use of Lap3 as a simple and portable sensor and have led to its commercial use on a worldwide scale. 

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],... 

All ion-exchanger membranes with fixed ion-exchanger sites are porous to a certain degree (in contrast to liquid membranes and to membranes of ion-selective electrodes based on solid or glassy electrolytes, such as a single crystal of lanthanum fluoride). 

Lanthanum Carbonate (Fesrenol) [Renal GU Agent/ Phosphate Binder] Uses Hyperphosphatemia in renal Dz Action Phosphate binder Dose 750-1500 mg PO daily -5- doses, w/ or immediately after meal titrate q2-3wk based on P04 levels Caution [C, /-] No data in GI Dz Disp Chew tabs SE NA, graft occlusion, HA, BP EMS N/V is common, monitor for hypovolemia and electrolyte disturbances OD May cause extension of nl SEs symptomatic and supportive... 

Marko Hrovat, Ariane Ahmad-Khanlou, Zoran Samadzija, Janez Hole, Interactions between lanthanum gallate based solid electrolyte and ceria , Materials Research Bulletin, 34[12/13], 2027-2034 (1999). 

The beginnings of the SOFC are recorded in an early East German University patent (Mobius and Roland, 1968) which shows awareness of many of the variables still being worked upon today. The oxides of lanthanum, zirconium, yttrium, samarium, europium, terbium, ytterbium, cerium and calcium are mentioned as candidate electrolyte materials. The proposed monolithic planar arrangement has, however, been abandoned by many companies, on the example of Allied Signal. One notable exception is a reversion to a circular planar concept by Ceramic Fuel Cells of Australia, UK (Section 4.7). The Rolls-Royce all-ceramic fuel cell (Section 4.3), which is monolithic and has one compliant feature, namely a gap, is a major exception. One modern trend is towards lower SOFC temperatures, with the intermediate-temperature IT/SOFC allowing the use of cell and stack arrangements with some flexibility and manoeuvrability based on new electrolytes, metallic flow plates, electrodes and interconnects. 

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