Ceramics lithium

Molten carbonate fuel cells (MCFCs) are currently being developed for natural gas and coal-based power plants for electrical utility, industrial, and military applications. MCFCs are high-temperature fuel cells that use an electrolyte composed of a molten carbonate salt mixture suspended in a porous, chemically inert ceramic lithium aluminium oxide (LiAI02) matrix. Since they operate at extremely high temperatures of 650°C and above, non-precious metals can be used as catalysts at the anode and cathode, reducing costs. 

Yamazoe, N., and Miura, N. 1996. Dynamically compacted rechargeable ceramic lithium batteries. Solid State Ionics 86-88, 897-902. 

Other binary aluminates include magnesium spinels that are used extensively as castable refractory ceramics. Lithium aluminates are used, potentially, in fuel cells and as materials for new types of nuclear reactors. Again, these applications reflect the refractory nature of aluminates and their chemical resistance. 

Lithium has the lowest density (0.53 gcm ) of all known metals. It is used in the manufacture of alloys, and in certain glasses and ceramics. Lithium carbonate is used in the treatment of manic-depressive disorders, although large amounts of lithium salts damage the central nervous system. 

Properties of Pressed Glass-Ceramic (Lithium Disilicate) of IPS EMPRESS 2 in Comparison to IPS EMPRESS (Layering Technique) (Leucite Glass-Ceramic) ... 

Glass-Ceramics. Lithium aluminosilicate and magnesium aluminosilicate glass compositions form the bases for several families of commercially important glass-ceramic products, as described in Sec. 6.2.7. 

The ceramic lithium ion conductor p-LigPS4 has a disordered and nanoporous structure that leads to an enhancement in ionic conductivity... 

Uses. Lithium fluoride is used primarily in the ceramic industry to reduce firing temperatures and improve resistance to thermal shock, abrasion, and acid attack (see Ceramics). Another use of LiF is in flux compositions with other fluorides, chlorides, and borates for metal joining (17) (see Solders). 

Simple Silicates. The most important simple siUcate glass-ceramics are based on lithium metasiUcate [10102-24-6] Li SiO lithium disiUcate... 

PetaHte, also a monoclinic lithium aluminum siHcate, LiAlSi O Q, has a theoretical Li O content of 4.88%. Commercial ores usually contain 3.5—4.5% Li O without concentration and ate a preferred source of lithia for use in ceramics and specialty gla2es. PetaHte is monoclinic and has a density of 2.4—2.5 g/cm. Heating to high temperature results in an irreversible phase change to a P-spodumene—Si02 soHd solution that could provide an extractable source... 

Lithium tetraborate [1303-94-2], is used as a flux in ceramics and in x-ray fluorescence spectroscopy. The salt has also been proposed for... 

Lithium carbonate is used to prepare Hthium aluminosiHcate glass ceramics which have low thermal coefficients of expansion, allowing use over a wide temperature range. It also finds uses in specialty glasses and enamels. 

Development of practical and low cost separators has been an active area of ceU development. CeU separators must be compatible with molten lithium, restricting the choice to ceramic materials. Early work employed boron nitride [10043-11-5] BN, but a more desirable separator has been developed using magnesium oxide [1309-48-4], MgO, or a composite ofMgO powder—BN fibers. Corrosion studies have shown that low carbon steel or... 

About 65% of the lithium is used as a ceU-bath additive in aluminum production and in ceramics and glass. Lithium batteries enjoy increasing popularity leading to steady growth in this market. Other uses are in lubricants and synthetic mbber (46). Since lithium is a light, strong metal, it finds apphcations in aerospace metals and alloys where a light metal is needed (see Lithiumand lithium compounds). 

Figure 9.20 shows the setup for a symmetric plate impact test. The projectile here has a facing plate of ceramic and is backed with a low-density foam, for support of the ceramic during launch. The facing plate of the target is also made of ceramic. The lithium fluoride slab, which backs the target sample, serves as a window for the laser velocity interferometer (VISAR) that measures the time-resolved particle velocity at the sample/window interface. 

Good results are obtained with oxide-coated valve metals as anode materials. These electrically conducting ceramic coatings of p-conducting spinel-ferrite (e.g., cobalt, nickel and lithium ferrites) have very low consumption rates. Lithium ferrite has proved particularly effective because it possesses excellent adhesion on titanium and niobium [26]. In addition, doping the perovskite structure with monovalent lithium ions provides good electrical conductivity for anodic reactions. Anodes produced in this way are distributed under the trade name Lida [27]. The consumption rate in seawater is given as 10 g A ar and in fresh water is... 

Fig. 4.52. SIMS and IBSCA depth profiles of the altered layer region of a lithium aluminosilicate (LAS) glass ceramic (conditions SkeVAr" ).

The contribution to the stress from electromechanical coupling is readily estimated from the constitutive relation [Eq. (4.2)]. Under conditions of uniaxial strain and field, and for an open circuit, we find that the elastic stiffness is increased by the multiplying factor (1 -i- K ) where the square of the electromechanical coupling factor for uniaxial strain, is a measure of the stiffening effect of the electric field. Values of for various materials are for x-cut quartz, 0.0008, for z-cut lithium niobate, 0.055 for y-cut lithium niobate, 0.074 for barium titanate ceramic, 0.5 and for PZT-5H ceramic, 0.75. These examples show that electromechanical coupling effects can be expected to vary from barely detectable to quite substantial. 

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