Lithium density

Regarding the reversible capacity of disordered carbons, we found that lithium is mainly in a quasi-metallic state, another minor part being in a state comparable to intercalation. If we consider that the lithium density in the intercalated domains is comparable to that of graphite, we can conclude that the enhanced reversible capacity of the disordered carbons is related with the quasi-metallic state of lithium. In this paper, we postulate that the electron density of the quasi-metallic lithium clusters is related with the size of the neighbour carbon layers. In future work, we plan to investigate different materials in order to determine if there is any relationship between the reversible capacity and the fringe length. 

A small cube of lithium (density = 0.535 g/cm )measuring 1.0 mm on each edge is added to 0.500 L of water. The following reaction occurs ... 

Gr. lithos, stone) Discovered by Arfvedson in 1817. Lithium is the lightest of all metals, with a density only about half that of water. 

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... 

Like the other alkah metals (45), lithium has appreciable solubiUty in Hquid ammonia. A saturated solution at —33.2° C contains 15.7 mol lithium in 1000 g of ammonia, and at 19°C has a density of 0.477, lower than that of any other known Hquid. Lithium reacts readily in Hquid ammonia to form... 

Metallurgy. Lithium forms alloys with numerous metals. Early uses of lithium alloys were made in Germany with the production of the lead alloy, BahnmetaH (0.04% Li), which was used for bearings for railroad cars, and the aluminum alloy, Scleron. In the United States, the aluminum alloy X-2020 (4.5% Cu, 1.1% Li, 0.5% Mn, 0.2% Cd, balance Al) was introduced in 1957 for stmctural components of naval aircraft. The lower density and stmctural strength enhancement of aluminum lithium alloys compared to normal aluminum alloys make it attractive for uses in airframes. A distinct lithium—aluminum phase (Al Li) forms in the alloy which bonds tightly to the host aluminum matrix to yield about a 10% increase in the modules of elasticity of the aluminum lithium alloys produced by the main aluminum producers. The density of the alloys is about 10% less than that of other stmctural aluminum alloys. 

Lithium magnesium alloys, developed during World War 11, have found uses in aerospace appHcations. Lithium alters the crystallization of the host magnesium from the normal hexagonal stmcture to the body-centered cubic stmcture, with resultant significant decreases in density and increases in ductibiHty. 

Refractive Index. The effect of mol wt (1400-4000) on the refractive index (RI) increment of PPG in ben2ene has been measured (167). The RI increments of polyglycols containing aUphatic ether moieties are negative drj/dc (mL/g) = —0.055. A plot of RI vs 1/Af is linear and approaches the value for PO itself (109). The RI, density, and viscosity of PPG—salt complexes, which maybe useful as polymer electrolytes in batteries and fuel cells have been measured (168). The variation of RI with temperature and salt concentration was measured for complexes formed with PPG and some sodium and lithium salts. Generally, the RI decreases with temperature, with the rate of change increasing as the concentration increases. 

Al—Li. Ahoys containing about two to three percent lithium [7439-93-2] Li, (Fig. 15) received much attention in the 1980s because of their low density and high elastic modulus. Each weight percent of lithium in aluminum ahoys decreases density by about three percent and increases elastic modulus by about six percent. The system is characteri2ed by a eutectic reaction at 8.1% Li at 579°C. The maximum soHd solubiHty is 4.7% Li. The strengthening precipitate in binary Al—Li ahoys is metastable Al Li [12359-85-2] having the cubic LI2 crystal stmcture, and the equhibrium precipitate is complex cubic... 

High energy density batteries with long shelf life, developed originally for military use, are based on lithium and thionyl chloride. These batteries are used ia backup or standby power sources for computer, missile, and telephone systems (191,192). 

Fig. 25. Lithium—sulfur dioxide and lithium —tbionyl chloride high rate batteries profile with (a) power density vs energy density, and (b) specific power vs...

Lithium—Thionyl Chloride Cells. Lidiium—thionyi chloride cells have very high energy density. One of the main reasons is the nature of the ceU reaction. 

Table 1. Theoretical Energy Densities for Rechargeable Lithium Systems...

Coin and Button Cell Commercial Systems. Initial commercialization of rechargeable lithium technology has been through the introduction of coin or button cells. The eadiest of these systems was the Li—C system commercialized by Matsushita Electric Industries (MEI) in 1985 (26,27). The negative electrode consists of a lithium alloy and the positive electrode consists of activated carbon [7440-44-0J, carbon black, and binder. The discharge curve is not flat, but rather slopes from about 3 V to 1.5 V in a manner similar to a capacitor. Use of lithium alloy circumvents problems with cycle life, dendrite formation, and safety. However, the system suffers from generally low energy density. 

Lithium Hypochlorite. High purity, anhydrous lithium hypochlorite [13840-33-0] LiOCl, is a white, lightweight, dusty, hygroscopic, and corrosive powder. The monohydrate is free-flowing, nondusty, and of reasonable density. The presence of diluents such as salt, sodium, and potassium sulfates reduces dustiness, increases bulk density, reduces reactivity, and improves storage stabiUty. The commercial product is marketed in this form. 

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