Solid oxide fuel cells temperature

Solid Oxide Fuel Cell temperature (K) setpoint temperature (K) air pre-heating temperature (K) thiekness of the anode layer (em) thiekness of the eathode layer (em) eell voltage (V) diffusion overpotential (V)... 

Solid Oxide Fuel Cell In SOF(7s the electrolyte is a ceramic oxide ion conductor, such as vttriurn-doped zirconium oxide. The conduetKity of this material is 0.1 S/ern at 1273 K (1832°F) it decreases to 0.01 S/ern at 1073 K (1472°F), and by another order of magnitude at 773 K (932°F). Because the resistive losses need to be kept below about 50 rn, the operating temperature of the... 

Solid oxide fuel cells consist of solid electrolytes held between metallic or oxide elecU odes. The most successful fuel cell utilizing an oxide electrolyte to date employs Zr02 containing a few mole per cent of yttrium oxide, which operates in tire temperature range 1100-1300 K. Other electrolytes based... 

Current availability of individual lanthanides (plus Y and La) in a state of high purity and relatively low cost has stimulated research into potential new applications. These are mainly in the field of solid state chemistry and include solid oxide fuel cells, new phosphors and perhaps most significantly high temperature superconductors... 

One leading prototype of a high-temperature fuel cell is the solid oxide fuel cell, or SOFC. The basic principle of the SOFC, like the PEM, is to use an electrolyte layer with high ionic conductivity but very small electronic conductivity. Figure B shows a schematic illustration of a SOFC fuel cell using carbon monoxide as fuel. 

The tape-casting method makes possible the fabrication of films in the region of several hundred micrometers thick. The mechanical strength allows the use of such a solid electrolyte as the structural element for devices such as the high-temperature solid oxide fuel cell in which zirconia-based solid electrolytes are employed both as electrolyte and as mechanical separator of the electrodes. 

This reaction is of great technological interest in the area of solid oxide fuel cells (SOFC) since it is catalyzed by the Ni surface of the Ni-stabilized Zr02 cermet used as the anode material in power-producing SOFC units.60,61 The ability of SOFC units to reform methane "internally", i.e. in the anode compartment, permits the direct use of methane or natural gas as the fuel, without a separate external reformer, and thus constitutes a significant advantage of SOFC in relation to low temperature fuel cells. 

High-temperature solid-oxide fuel cells (SOFCs). The working electrolyte is a solid electrolyte based on zirconium dioxide doped with oxides of yttrium and other metals the working temperatures are 800 to 1000°C. Experimental plants with a power of up to lOOkW have been built with such systems in the United States and Japan. 

Double Substitution In such processes, two substitutions take place simultaneously. For example, in perovskite oxides, La may be replaced by Sr at the same time as Co is replaced by Fe to give solid solutions Lai Sr Coi yFey03 5. These materials exhibit mixed ionic and electronic conduction at high temperatures and have been used in a number of applications, including solid oxide fuel cells and oxygen separation. 

There are six different types of fuel cells (Table 1.6) (1) alkaline fuel cell (AFC), (2) direct methanol fuel cell (DMFC), (3) molten carbonate fuel cell (MCFC), (4) phosphoric acid fuel cell (PAFC), (5) proton exchange membrane fuel cell (PEMFC), and (6) the solid oxide fuel cell (SOFC). They all differ in applications, operating temperatures, cost, and efficiency. 

Singh, P., Ruka, R.J., and George, R.A Direct utilization of hydrocarbon fuels in high temperature solid oxide fuel cells, In Proc 24 1 intersociety energy conversion engineering conference. Pub. Institute of Electrical and Electronics Engineers, New York, 1989, pp 1553 1563. 

These effects can all be enhanced if the point defects interact to form defect clusters or similar structures, as in Fej xO above or U02, (Section 4.4). Such clusters can suppress phase changes at low temperatures. Under circumstances in which the clusters dissociate, such as those found in solid oxide fuel cells, the volume change can be considerable, leading to failure of the component. 

A fuel cell is a form of battery. An ordinary battery consists of internal reactants that are converted into electrical energy, whereas in a fuel cell the chemical reactants are supplied from an external source. There are several designs of fuel cell, one of which is the solid oxide fuel cell (SOFC). These employ calcia- or yttria-stabilized zirco-nia. The cells operate at temperatures of about 900°C, this high temperature being needed to maintain a high enough oxygen transport for useful cell output. 

S. C. Singhal and K. Kendall, High Temperature Solid Oxide Fuel Cells, Fundamentals, Design, and Application, 2003 Elsevier, ISBN 1856173879. 

FIGURE 2.8 (a) Porosity versus sintering temperatures for Ni-YSZ cermets sintered for different times (2, 4, and 6 h) (b) Anode conductivity versus porosity for the Ni-YSZ cermets with Ni to YSZ volume ratio of 40 60. (From Pratihar, S.K. et al., Proceedings of the Sixth International Symposium on Solid Oxide Fuel Cells, 99(19) 513—521. Reproduced by permission of ECS-The Electrochemical Society.)... 

Primdahl S, Sprensen BF, and Mogensen M. Effect of nickel oxide/yttria-stabilized zirconia anode precursos sintering temperature on the properties of solid oxide fuel cells. J Am Ceram Soc 2000 83 489 -94. 

Feduska W and Isenberg AO. High temperature solid oxide fuel cell—technical results. J Power Sources 1983 10 89-102. 

Mori M, Yamamoto T, Itoh H, and Watanabe T. Compatibility of alkaline earth metal (Mg,Ca,Sr)-doped lanthanum chromites as separators in planar-type high-temperature solid oxide fuel cells. J. Mater. Sci. 1997 32 2423-2431. 

Mori K, Miyamoto H, Takenobu K, and Matsudaira T. Controlling the chromite expansion in reducing atmosphere at high temperature. In AJ. McEvoy, editor. European Solid Oxide Fuel Cell Forum Proceedings Vol. 2. Lucerne, Switzerland The European Fuel Cell Forum, 2000 875-880. 

J.E. O Brien, J.S. Herring, P.A. Lessing, and C.M. Stoots, High Temperature Steam Electrolysis from Advanced Nuclear Reactors using Solid Oxide Fuel Cells, presented at the First International Conference on Fuel Cell Science, Engineering, and Technology, Rochester, NY, April 21-23, 2003. 

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