Lithium carbon

Propargylic alcohol, after lithiation, reacts with CO2 to generate the lithium carbonate 243, which undergoes oxypalladation. The reaction of allyl chloride yields the cyclic carbonate 244 and PdC. By this reaction hydroxy and allyl groups are introduced into the triple bond to give the o-allyl ketone 245[129]. Also the formation of 248 from the keto alkyne 246 with CO2 via in situ formation of the carbonate 247 is catalyzed by Pd(0)[130]. 

Manufacture. Lithium fluoride is manufactured by the reaction of lithium carbonate or lithium hydroxide with dilute hydrofluoric acid. If the lithium carbonate is converted to the soluble bicarbonate, insolubles can be removed by filtration and a purer lithium fluoride can be made on addition of hydrofluoric acid (12). High purity material can also be made from other soluble lithium salts such as the chloride or nitrate with hydrofluoric acid or ammonium bifluoride (13). 

Whereas new appHcations of lithium compounds were developed, commercial growth was slow. In 1953 worldwide sales of lithium products, expressed as lithium carbonate, were only ca 1000 metric tons (2). In 1954 the U.S. lithium industry underwent a sudden, very large expansion when the U.S. Atomic Energy Commission required large amounts of lithium hydroxide [1310-65-2] for its nuclear weapons program (see Nuclearreactors). Three domestic producers built 4500-t/yr plants to meet contract commitments with the U.S. government. When these government contracts ended in 1960, capacity exceeded demand and several operations were discontinued. 

One ion-exchange process, which was used for several years by Quebec Lithium Corp., is based on the reaction of P-spodumene with an aqueous sodium carbonate solution in an autoclave at 190—250°C (21). A slurry of lithium carbonate and ore residue results, and is cooled and treated with carbon dioxide to solubilize the lithium carbonate as the bicarbonate. The ore residue is separated by filtration. The filtrate is heated to drive off carbon dioxide resulting in the precipitation of the normal carbonate. 

Lithium Acetate. Lithium acetate [546-89 ] is obtained from reaction of lithium carbonate or lithium hydroxide and acetic acid. Crystalline lithium acetate dihydrate [6108-1 7a(/, CH2C02Li 2H20, melts congmentiy in its own water of crystallization at 57.8°C. The anhydrous salt [646-89-4] melts... 

Lithium Carbonate. Lithium carbonate [554-13-2], Li2C02, is produced in industrial processes from the reaction of sodium carbonate and Hthium sulfate or Hthium chloride solutions. The reaction is usually performed at higher temperatures because aqueous Hthium carbonate solubiHty decreases with increasing temperatures. The solubiHty (wt %) is 1.52% at 0°C, 1.31% at 20°C, 1.16% at 40°C, 1.00% at 60°C, 0.84% at 80°C, and 0.71% at 100°C. Lithium carbonate is the starting material for reactions to produce many other Hthium salts, including the hydroxide. Decomposition of the carbonate occurs above the 726°C melting point. 

Lithium carbonate addition to HaH-Heroult aluminum ceU electrolyte lowers the melting point of the eutectic electrolyte. The lower operating temperatures decrease the solubiHty of elemental metals in the melt, allowing higher current efficiencies and lower energy consumption (55). The presence of Hthium also decreases the vapor pressure of fluoride salts. 

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. 

Lithium Bromide. Lithium biomide [7550-35-8] LiBi, is piepaied from hydiobiomic acid and lithium carbonate oi lithium hydroxide. The anhydrous salt melts at 550°C and bods at 1310°C. Lithium bromide is a component of the low melting eutectic electrolytes ia high temperature lithium batteries. 

Lithium Iodide. Lithium iodide [10377-51 -2/, Lil, is the most difficult lithium halide to prepare and has few appHcations. Aqueous solutions of the salt can be prepared by carehil neutralization of hydroiodic acid with lithium carbonate or lithium hydroxide. Concentration of the aqueous solution leads successively to the trihydrate [7790-22-9] dihydrate [17023-25-5] and monohydrate [17023-24 ] which melt congmendy at 75, 79, and 130°C, respectively. The anhydrous salt can be obtained by carehil removal of water under vacuum, but because of the strong tendency to oxidize and eliminate iodine which occurs on heating the salt ia air, it is often prepared from reactions of lithium metal or lithium hydride with iodine ia organic solvents. The salt is extremely soluble ia water (62.6 wt % at 25°C) (59) and the solutions have extremely low vapor pressures (60). Lithium iodide is used as an electrolyte ia selected lithium battery appHcations, where it is formed in situ from reaction of lithium metal with iodine. It can also be a component of low melting molten salts and as a catalyst ia aldol condensations. 

Lithium Hydroxide. Lithium hydroxide monohydrate [1310-66-3], Li0H-H2 0, is prepared industrially from the reaction of lithium carbonate and calcium hydroxide in aqueous slurries. The calcium carbonate is subsequently separated to yield a lithium hydroxide solution from which lithium hydroxide monohydrate can be crystallized. Lithium hydroxide is the least soluble alkaH hydroxide, and solubiHty varies Htfle with temperature. 

Lithium Silicate. Lithium siUcate [10102-24-6], Li2Si02, is formed from calcination of lithium carbonate or hydroxide using finely ground... 

Lithium ion is commonly ingested at dosages of 0.5 g/d of lithium carbonate for treatment of bipolar disorders. However, ingestion of higher concentrations (5 g/d of LiCl) can be fatal. As of this writing, lithium ion has not been related to industrial disease. However, lithium hydroxide, either dHectly or formed by hydrolysis of other salts, can cause caustic bums, and skin contact with lithium haHdes can result in skin dehydration. Organolithium compounds are often pyrophoric and requHe special handling (53). 

Lithium niobate [12031 -63-9] Nb20 or LiNbO, is prepared by the soHd-state reaction of lithium carbonate with niobium pentoxide. After... 

Polyester resins can also be rapidly formed by the reaction of propylene oxide (5) with phthaUc and maleic anhydride. The reaction is initiated with a small fraction of glycol initiator containing a basic catalyst such as lithium carbonate. Molecular weight development is controlled by the concentration of initiator, and the highly exothermic reaction proceeds without the evolution of any condensate water. Although this technique provides many process benefits, the low extent of maleate isomerization achieved during the rapid formation of the polymer limits the reactivity and ultimate performance of these resins. 

Treatment of Manic—Depressive Illness. Siace the 1960s, lithium carbonate [10377-37-4] and other lithium salts have represented the standard treatment of mild-to-moderate manic-depressive disorders (175). It is effective ia about 60—80% of all acute manic episodes within one to three weeks of adrninistration. Lithium ions can reduce the frequency of manic or depressive episodes ia bipolar patients providing a mood-stabilising effect. Patients ate maintained on low, stabilising doses of lithium salts indefinitely as a prophylaxis. However, the therapeutic iadex is low, thus requiring monitoring of semm concentration. Adverse effects iaclude tremor, diarrhea, problems with eyes (adaptation to darkness), hypothyroidism, and cardiac problems (bradycardia—tachycardia syndrome). 

Other Drugs. Agents not considered to be CNS stimulants yet employed for the treatment of certain types of depression includes lithium carbonate for the treatment of bipolar disorder. In most patients, lithium is the sole agent used to control manic behavior and is very effective (see... 

Lithium. In the lithium carbonate treatment of certain psychotic states, a low incidence (3.6%) of hypothyroidism and goiter production have been observed as side effects (6,36) (see Psychopharmacologicalagents). It has been proposed that the mechanism of this action is the inhibition of adenyl cyclase. Lithium salts have not found general acceptance in the treatment of hyperthyroidism (see Lithiumand lithium compounds). 

Recovery Process. Lithium is extracted from brine at Silver Peak Marsh, Nevada, and at the Salar de Atacama, Chile. Both processes were developed by Foote Mineral Corp. The process at Silver Peak consists of pumping shallow underground wells to solar ponds where brines are concentrated to over 5000 ppm. Lithium ion is then removed by precipitation with soda ash to form a high purity lithium carbonate [554-13-2]. At the Atacama, virgin brine with nearly 3000 ppm lithium is concentrated to near saturation in lithium chloride [7447-41 -8]. This brine is then shipped to Antofagasta, Chile where it is combined with soda ash to form lithium carbonate. 

The United States produces and consumes about one-half of all the wodd production. Ore grades for the two principal nonbrine producers are becoming poor, and imports of brine-based lithium carbonate are increa sing. 

Lithium Chloride. Of the metal haUdes, calcium bromide [7789-41-5] CaBr2, ziac chloride [7646-85-7] ZnCl2, CaCl2, and lithium chloride [7447-41-8] LiCl, (Class 1, nonregenerative) are the most effective for water removal (4). AH are available ia the form of dehquescent crystals. The hydrates of LiCl are LiCl-nH2 O, where n = 1, 2, or 3. Lithium chloride solutions are more stable ia air and less corrosive than the other metal haUdes. The high solubihty of lithium carbonate [554-13-2] Li2C02, usually eliminates scale formation problems (see LiTHlUM COMPOUNDS). 

Figure 3 shows the voltage-capacity relation for lithium/carbon electrochemieal cells made from representative materials from each of the three regions of Fig. 2. 

For convenience and simplicity, the electrochemical study of electrode materials is normally made in lithium/(eleetrode material) eells. For earbonaeeous materials, a hthium/carbon eell is made to study electroehemical properties, sueh as eapaeity, voltage, eyeling life, etc.. Lithium/carbon coin cells use metallie lithium foil as the anode and a partieular carbonaceous material as the... 

Lithium/carbon cells are typically made as coin cells. The lithium/carbon coin cell consists of several parts, including electrodes, separator, electrolyte and cell hardware. To construct a coin cell, we first must prepare each part separately. Successful cells will lead to meaningful results. The lithium/carbon coin cells used metallic lithium foil as the anode and a carbonaceous material as the cathode. The metallic lithium foil, with a thickness of 125 pm, was provided by Moli Energy (1990) Ltd.. Idie lithium foil is stored in a glove-box under an argon atmosphere to avoid oxidation. 

Freshly assembled lithium/carbon coin cells typically have voltages between 2.8 and 3.4 volts. The cells are in their fully charged state which means that no lithium is inserted in the carbon anode. Then the coin cells are tested with computer-controlled constant-current cyclers having currents stable to 1%. The cells are placed in thermostats at a particular set temperature v/hich is stable to 0.1°C during the test. Most of our cells were tested at 30°C. 

Fig. 20. Voltage-capacity profiles for the second cycles of lithium/carbon cells made from ENR resin heated at different temperatures as indicated.

F igure 21 compares the voltage-capacity profiles for the second cycle of lithium/carbon electrochemical cells made from OXY, a representative hard carbon, and those for samples made from CRO, a representative soft carbon. 

Two electrochemical lithium/carbon cells were made for each of the pyrolyzed materials. We used currents of 18.5 mA/g (20-hour rate) for the fust three charge-discharge cycles and 37 mA/g (10-hour rate) for the extended cycling test. 

---