Solid oxide fuel cell cathodes

Solid oxide fuel cell, SOFC anodes, 97 catalysis in, 98,410 cathodes, 96... 

This presentation reports some studies on the materials and catalysis for solid oxide fuel cell (SOFC) in the author s laboratory and tries to offer some thoughts on related problems. The basic materials of SOFC are cathode, electrolyte, and anode materials, which are composed to form the membrane-electrode assembly, which then forms the unit cell for test. The cathode material is most important in the sense that most polarization is within the cathode layer. The electrolyte membrane should be as thin as possible and also posses as high an oxygen-ion conductivity as possible. The anode material should be able to deal with the carbon deposition problem especially when methane is used as the fuel. 

Although the superconducting state of this material has attracted considerable attention, the metallic state is also of interest. For instance, metallic samples are being explored for use as cathode materials in solid oxide fuel cells (Section 6.10). 

The Brouwer diagram approach can be illustrated with reference to the perovskite structure oxide system BaYbvPr VC>3, which has been explored as a potential cathode material for use in solid oxide fuel cells. The parent phase... 

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 solid oxide fuel cells (SOFCs), the cathode is the material where pure oxygen or oxygen from air is reduced through the following electrochemical reaction [1]... 

FIGURE 6.5 Tubular cathode-supported solid oxide fuel cell developed by Siemens Power Generation [48]. Reprinted from [48] with permission from Elsevier. 

Hart NT, Brandon NP, Day MJ, and Shemilt JE. Functionally graded cathodes for solid oxide fuel cells. J. Mat. Sci. 2001 36 1077-1085. 

Lee KT and Manthiram A. Synthesis and characterization of NdQjSrQ.jCOj MnyOj (0temperature solid oxide fuel cells. J. Power Sources 2006 158 1202-1208. 

Shao Z and Halle SM. A high-performance cathode for the next generation of solid oxide fuel cells. Nature 2004 431 170-173. 

Bansal NP and Zhong Z. Combustion synthesis of Sm0 5Sr0 5Co03 x and Lao 6Sr04CoO3 x nanopowders for solid oxide fuel cell cathodes. J. Power Sources 2006 158 148-153. 

Labrincha JA, Li-Jian M, dos Santos MP, Marques FMB, and Frade JR. Evaluation of deposition techniques of cathode materials for solid oxide fuel cells. Mater Res. Bull. 1993 28 101-109. 

In fuel cells, the combustion energy of hydrocarbons can be converted directly into electrical energy. At the fuel cell anode, the hydrocarbon is in most cases converted to carbon dioxide because the intermediates are more easily oxidized than the starting hydrocarbon (Eq. 9a) at the fuel cell cathode oxygen is reduced to water (Eq. 9b). Most fuel cell research has involved the use of hydrogen as fuel. However, solid oxide fuels cells (SOCFs) can operate at higher temperature and can... 

Tubular Solid Oxide Fuel Cell (TSOFC) The electrolyte in this fuel cell is a solid, nonporous metal oxide, usually Y203-stabilized Z1O2. The cell operates at 1000°C where ionic conduction by oxygen ions takes place. Typically, the anode is Co-Zr02 or Ni-Zr02 cermet, and the cathode is Sr-doped LaMnOs. 

Figure 8-1 Solid Oxide Fuel Cell Designs at the Cathode...

Factors Governing Oxygen Reduction in Solid Oxide Fuel Cell Cathodes Stuart B. Adler... 

A solid oxide fuel cell (SOFC) consists of two electrodes anode and cathode, with a ceramic electrolyte between that transfers oxygen ions. A SOFC typically operates at a temperature between 700 and 1000 °C. at which temperature the ceramic electrolyte begins to exhibit sufficient ionic conductivity. This high operating temperature also accelerates electrochemical reactions therefore, a SOFC does not require precious metal catalysts to promote the reactions. More abundant materials such as nickel have sufficient catalytic activity to be used as SOFC electrodes. In addition, the SOFC is more fuel-flexible than other types of fuel cells, and reforming of hydrocarbon fuels can be performed inside the cell. This allows use of conventional hydrocarbon fuels in a SOFC without an external reformer. 

For the purposes of review. Figure 1 illustrates the basic function of the cathode in a solid oxide fuel cell. Whether acting alone or as part of a stack of cells, each cell consist of a free-standing or supported membrane of an oxygen-ion-conducting electrolyte, often yttria-stabilized zirconia (YSZ). Oxygen, which is fed (usually as air) to one side of the membrane, is reduced by the cathode to oxygen ions via the overall half-cell reaction... 

Figure 1. Schematic showing the roles of anode, cathode, and electrolyte in a solid oxide fuel cell (SOFC).

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