Electrolyte zirconium oxide

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 use zirconium oxide stabilized with yttrium as an electrolyte and have an OT of 850 to 1000°C. 

While several types of oxygen sensors have been investigated for automotive use, the most common type in commercial use consists of a galvanic cell with a fully or partially stabilized zirconium oxide electrolyte. 

Another oxide family involving zirconium oxide has been examined as a possible alternative to YSZ as electrolytes in SOFCs. They are the pyrochlore solid solutions of the general formula M2Zr207, where M is a rare-earth metal [25-29]. Zirconium can be substituted by a transition metal such as titanium. Moon et al. [29] have in-... 

In all of the discussion of this chapter we have used an aqueous solution as the electrolyte, and electrodes suitable to those aqueous solutions. However, cells are not limited to aqueous solutions. Indeed, other solvents have been used for which liquid ammonia would be an example. Molten salts, such as mixtures of lithium chloride and potassium chloride, have been used for the study of cells at high temperatures. Some studies have been made at higher temperatures, in which solid electrolytes were used. Electrodes compatible with such solvents have also been devised. For example, a zirconium-zirconium oxide electrode stabilized with calcium oxide was used to measure the oxygen potential in nonstoichiometric metal oxides. However, no matter what the electrolytes or the electrodes are, the principles discussed in this chapter such as reversibility and proper measurement must be followed. 

Solid oxide fuel cell (SOFC)—Solid zirconium oxide electrolyte it is suited for large-scale central electric power plants. 

For the solid oxide fuel cells (SOFCs), a number of environmentally critical items have been identified (Zapp, 1996). The carrier sheet electrolyte may be produced from yttrium-stabilised zirconium oxide with added electrodes made of, e.g., LaSrMn-perovskite and NiO-cermet. Nitrates of these substances are used in manufacturing, and metal contamination of wastewater is a concern. The high temperature of operation makes the assembly very difficult to disassemble for decommissioning, and no process for recovering yttrium from the YSZ electrolyte material is currently known. 

CARRE, Inc. also produces a series of dynamic hyperfiltration membranes on porous metal tubes. The major product is the ZOPA hyperfilter hydrous zirconium oxide-poly(acrylic acid) on porous stainless steel tubes. The hyperfiltration properties of the ZOPA membranes are also listed in Table I. The most attractive properties of the ZOPA membrane are durability at temperatures of at least 100 C, high membrane permeability, and reformation capability. The hydrous zirconium oxide-poly(acrylic acid) membranes provide modest rejection of simple electrolytes. Although the membrane permeability is high compared to most cast reverse osmosis /hyper-... 

Milonjic, S.K., Ilic, Z.E., and Kopccni, M.M., Sorption of alkali cations at the zirconium oxide/aqueous electrolyte interface. Colloids Surf., 6, 167, 1983. 

The lambda sensor, which is found in all motor cars with catalytic converters, is an oxygen probe based on the principle of selective electrodes. This sensor, which looks like a spark plug, has a zirconium oxide (zr02) membrane that behaves as a solid electrolyte. The external wall is in contact with the exhaust fumes while the Internal wall (the reference) is in contact with air. Between these two walls a PD appears, collected by two electrodes, which is indicative of the difference in oxygen concentrations. 

Yttria-doped zirconia and gadolinia-doped ceria oxygen ion conductors and strontium yttrium zirconium oxide proton conductors are being investigated as the solid electrolyte. 

Complex FCC oxides of the fluorite type represent oxygen-conduction solid electrolytes (SOE s). They comprise a typical class of materials for the manufacture of sensors of oxygen activity in complex gas mixtures, oxygen pumps, electrolyzers and high-temperature fuel elements. These materials are based on doped oxides of cerium and thorium, zirconium and hafnium, and bismuth oxide. Materials based on zirconium oxide, for example, yttrium stabilized zirconia (YSZ) are the most known and studied among them. This fact is explained both by their processibility and a wide spectrum of practical applications and by the possibility to conduct studies on single crystals, which have the commercial name "fianites" and are used in jewelry. 

SOLID ELECTROLYTES FROM STABILIZED ZIRCONIUM OXIDE THAT ARE DEVELOPED IN O.J.S.C. UKRAINIAN RESEARCH INSTITUTE OF REFRACTORIES NAMED AFTER A.S. BEREZHNOY ... 

Among the most important demands that are made for electrolytes on the basis of zirconium oxide is combination of high electrical conductivity with ageing stability in the range of operating temperatures (900-1000° C). 

YA. Gallego, a. Mendes, LM. Madeira, S.P. Nunes, Proton electrolyte membrane properties and direct methanol fuel-cell performance I. Characterization of hybrid sulfonated poly-(ether ether ketone)/zirconium oxide membranes. Journal [Pg.85]

Electrolyte KOH Solid polymer membrane H3PO4 Molten earbonate Doped zirconium oxide... 

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