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11 novembre 2011 5 11 /11 /novembre /2011 01:48

Lithium (/?l??i?m/ lith-ee-?m) is a soft, silver-white metal that belongs to the alkali metal group of chemical elements. It is represented by the symbol Li, and it has the atomic number 3. Under standard conditions it is the lightest metal and the least dense solid element. Sony VAIO VGN-Z620D Battery

Like all alkali metals, lithium is highly reactive and flammable. For this reason, it is typically stored in mineral oil. When cut open, lithium exhibits a metallic luster, but contact with moist air corrodes the surface quickly to a dull silvery gray, then black, tarnish.Sony VAIO VGN-Z620N/B Battery

Because of its high reactivity, lithium never occurs free in nature, and instead, only appears in compounds, which are usually ionic. Lithium occurs in a number of pegmatitic minerals, but due to its solubility as an ion is present in ocean water and is commonly obtained from brines and clays. Sony VAIO VGN-Z650N/B Battery

On a commercial scale, lithium is isolated electrolytically from a mixture of lithium chloride and potassium chloride.

The nuclei of lithium verge on instability, since the two stable lithium isotopes found in nature have among the lowestbinding energies per nucleon of all stable nuclides.Sony VAIO VGN-Z670N/B Battery

Because of its relative nuclear instability, lithium is less common in the solar system than 25 of the first 32 chemical elements even though the nuclei are very light in atomic weight.For related reasons, lithium has important links to nuclear physics. The transmutation of lithium atoms to helium in 1932 was the first fully man-made nuclear reaction, and lithium deuteride serves as a fusion fuel in staged thermonuclear weapons.Sony VAIO VGN-Z690CTO Battery

Lithium and its compounds have several industrial applications, including heat-resistant glass and ceramics, high strength-to-weight alloys used in aircraft, lithium batteries and lithium-ion batteries. These uses consume more than half of lithium production.

Trace amounts of lithium are present in all organisms. The element serves no apparent vital biological function, since animals and plants survive in good health without it.Sony VAIO VGN-Z690NAX Battery

Nonvital functions have not been ruled out. The lithium ion Li+administered as any of several lithium salts has proved to be useful as a mood-stabilizing drug due to neurological effectsof the ion in the human body.

Atomic and physical

Like the other alkali metals, lithium has a single valence electron that is easily given up to form a cation.Sony VAIO VGN-Z690PAB Battery

Because of this, it is a good conductor of heat andelectricity as well as a highly reactive element, though the least reactive of the even-more highly reactive alkali metals. Lithium's low reactivity compared to other alkali metals is thought to be due to the proximity of its valence electron to itsnucleus (the remaining two electrons in lithium's 1s orbital and are much lower in energy, and therefore they do not participate in chemical bonds). Sony VAIO VGN-Z690PCB Battery

Lithium metal is soft enough to be cut with a knife. When cut, it possesses a silvery-white color that quickly changes to gray due to oxidation.[2] While it has one of the lowest melting points among all metals (180 °C), it has the highest melting and boiling points of the alkali metals.Sony VAIO VGN-Z690PDB Battery

It is the lightest metal in the periodic table, so light that it can float on water and even on oil, and it is one of two metals that can. It has a very low density, of approximately 0.534 g/cm3, which gives sticks of the metal a similar heft todowels of a medium density wood, such as pine. It floats on water but also reacts with it.Sony VAIO VGN-Z690PEB Battery

It is the least dense of all elements that are not gasses at room temperature. The next lightest element is over 60% more dense (potassium, at 0.862 g/cm3). Furthermore, aside from helium andhydrogen, it is the least dense element in a solid or liquid state, being only 2/3 as dense asliquid nitrogen (0.808 g/cm3).Sony VAIO VGN-Z690PFB Battery

Lithium's coefficient of thermal expansion is twice that of aluminum and almost four times that of iron.It has the highest specific heat capacity of any solid element. Lithium is superconductivebelow 400 ?K at standard pressure and at higher temperatures (more than 9 K) at very high pressures (>20 GPa) At temperatures below 70 K, lithium, like sodium, undergoes diffusionless phase change transformations. Sony VAIO VGN-Z690YAD Battery

At 4.2 K it has a rhombohedral crystal system (with a nine-layer repeat spacing); at higher temperatures it transforms to face-centered cubic and then body-centered cubic. At liquid-helium temperatures (4 K) the rhombohedral structure is the most prevalent.Multiple allotropic forms have been reported for lithium at high pressures.Sony VAIO VGN-Z691Y/B Battery

Chemistry and compounds

Lithium reacts with water easily, but with noticeably less energy than other alkali metals do. The reaction forms hydrogen gas and lithium hydroxide in aqueous solution.Because of its reactivity with water, lithium is usually stored under cover of a viscous hydrocarbon, often petroleum jelly. Sony VAIO VGN-Z691Y/X Battery

Though the heavier alkali metals can be stored in less dense substances, such as mineral oil, lithium is not dense enough to be fully submerged in these liquids.In moist air, lithium rapidly tarnishes to form a black coating of lithium hydroxide (LiOH and LiOH·H2O), lithium nitride (Li3N) andlithium carbonate (Li2CO3, the result of a secondary reaction between LiOH and CO2).Sony VAIO VGN-Z698Y/X Battery

When placed over a flame, lithium compounds give off a striking crimson color, but when it burns strongly the flame becomes a brilliant silver. Lithium will ignite and burn in oxygen when exposed to water or water vapors.Lithium is inflammable, and it is potentially explosive when exposed to air and especially to water, though less so than the other alkali metals. Sony VAIO VGN-Z70B Battery

The lithium-water reaction at normal temperatures is brisk but not violent, the hydrogen produced will not ignite on its own. As with all alkali metals, lithium fires are difficult to extinguish, requiring dry powder fire extinguishers, specifically Class D type (see Types of extinguishing agents). Lithium is the only metal which reacts with nitrogen under normal conditions.Sony VAIO VGN-Z71JB Battery

Lithium has a diagonal relationship with magnesium, an element of similar atomic and ionic radius. Chemical resemblances between the two metals include the formation of a nitride by reaction with N2, the formation of an oxide (Li2O) and peroxide (Li2O2) when burnt in O2, salts with similar solubilities, and thermal instability of the carbonates and nitrides.Sony VAIO VGN-Z73FB Battery

The metal reacts with hydrogen gas at high temperatures to produce lithium hydride (LiH).

Other known binary compounds include the halides (LiF, LiCl, LiBr, LiI), and the sulfide (Li2S), the superoxide (LiO2), carbide(Li2C2). Many other inorganic compounds are known, where lithium combines with anions to form various salts: borates, amides,carbonate, nitrate, or borohydride (LiBH4). Sony VAIO VGN-Z790DKX Battery

Multiple organolithium reagents are known where there is a direct bond between carbon and lithium atoms effectively creating a carbanion that are extremely powerful bases and nucleophiles. In many of these organolithium compounds, the lithium ions tend to aggregate into high-symmetry clusters by themselves, which is relatively common for alkali cations.Sony VAIO VGN-Z790DMR Battery

Isotopes

Naturally occurring lithium is composed of two stable isotopes, 6Li and 7Li, the latter being the more abundant (92.5% natural abundance).Sony VAIO VGN-Z790DND Battery

Both natural isotopes have anomalously low nuclear binding energy per nucleon compared to the next lighter and heavier elements, helium and beryllium, which means that alone among stable light elements, lithium can produce net energy through nuclear fission.Sony VAIO VGN-Z820DB Battery

The two lithium nuclei have lower binding energies per nucleon than any other stable compound nuclides other than deuterium, and helium-3.As a result of this, though very light in atomic weight, lithium is less common in the solar system than 25 of the first 32 chemical elements.Sony VAIO VGN-Z820G/B Battery

Seven radioisotopes have been characterized, the most stable being 8Li with a half-life of 838 ms and 9Li with a half-life of 178 ms. All of the remaining radioactive isotopes have half-lives that are shorter than 8.6 ms. The shortest-lived isotope of lithium is 4Li, which decays through proton emission and has a half-life of 7.6 × 10?23 s.Sony VAIO VGN-Z890GLX Battery

7Li is one of the primordial elements (or, more properly, primordial nuclides) produced in Big Bang nucleosynthesis. A small amount of both 6Li and 7Li are produced in stars, but are thought to be burned as fast as produced.Additional small amounts of lithium of both 6Li and 7Li may be generated from solar wind, cosmic rays hitting heavier atoms, and from early solar system 7Be and 10Be radioactive decay.Sony VAIO VGN-Z890GMR Battery

While lithium is created in stars during the Stellar nucleosynthesis, it is further burnt. 7Li can also be generated in carbon stars.

Lithium isotopes fractionate substantially during a wide variety of natural processes, including mineral formation (chemical precipitation), metabolism, and ion exchange. Sony VAIO VGN-Z898H/X Battery

Lithium ions substitute for magnesium and iron in octahedral sites in clay minerals, where 6Li is preferred to 7Li, resulting in enrichment of the light isotope in processes of hyperfiltration and rock alteration. The exotic 11Li is known to exhibit a nuclear halo. The process known as laser isotope separation can be used to separate lithium isotopes.Sony VAIO VGN-Z90FS Battery

Astronomical

According to modern cosmological theory, lithium—as both of its stable isotopes lithium-6 and lithium-7—was among the 3 elements synthesized in the Big Bang. Sony VAIO VGN-Z90NS Battery

Though the amount of lithium generated in Big Bang nucleosynthesis is dependent upon the number of photons per baryon, for accepted values the lithium abundance can be calculated, and there is a "cosmological lithium discrepancy" in the Universe: older stars seem to have less lithium than they should, and some younger stars have far more.Sony VAIO VGN-Z90PS Battery

The lack of lithium in older stars is apparently caused by the "mixing" of lithium into the interior of stars, where it is destroyed.Furthermore, lithium is produced in younger stars. Though it transmutes into two atoms of helium due to collision with aproton at temperatures above 2.4 million degrees Celsius Sony VAIO VGN-Z90S Battery

(most stars easily attain this temperature in their interiors), lithium is more abundant than predicted in later-generation stars, for causes not yet completely understood.

Though it was one of the three first elements (together with helium and hydrogen) to be synthesized in the Big Bang, lithium, together with beryllium and boron are markedly less abundant than other nearby elements. Sony VAIO VGN-Z90US Battery

This is a result of the low temperature necessary to destroy lithium, and a lack of common processes to produce it.

Lithium is also found in brown dwarf stars and certain anomalous orange stars. Because lithium is present in cooler, less-massive brown dwarf stars, but is destroyed in hotter red dwarf stars, its presence in the stars' spectra can be used in the "lithium test" to differentiate the two, as both are smaller than the Sun.Sony VAIO VGN-Z91DS Battery

Certain orange stars can also contain a high concentration of lithium. Those orange stars found to have a higher than usual concentration of lithium (such as Centaurus X-4) orbit massive objects—neutron stars or black holes—whose gravity evidently pulls heavier lithium to the surface of a hydrogen-helium star, causing more lithium to be observed.Sony VAIO VGN-Z91JS Battery

Terrestrial

Although lithium is widely distributed on Earth, it does not naturally occur in elemental form due to its high reactivity.The total lithium content of seawater is very large and is estimated as 230 billion tonnes, where the element exists at a relatively constant concentration of 0.14 to 0.25 parts per million (ppm),or 25 micromolar;Sony VAIO VGN-Z91YS Battery

higher concentrations approaching 7 ppm are found near hydrothermal vents.

Estimates for crustal content range from 20 to 70 ppm by weight.In keeping with its name, lithium forms a minor part of igneous rocks, with the largest concentrations in granites. Sony VAIO VGN-Z92DS Battery

Granitic pegmatites also provide the greatest abundance of lithium-containing minerals, with spodumene and petalite being the most commercially viable sources. A newer source for lithium is hectorite clay, the only active development of which is through the Western Lithium Corporation in the United States.Sony VAIO VGN-Z92JS Battery

At 20 mg lithium per kg of Earth's crust, lithium is the 25th most abundant element. Nickel and lead have about the same abundance.

According to the Handbook of Lithium and Natural Calcium, "Lithium is a comparatively rare element, although it is found in many rocks and some brines, but always in very low concentrations. Sony VAIO VGN-Z92PS Battery

There are a fairly large number of both lithium mineral and brine deposits but only comparatively a few of them are of actual or potential commercial value. Many are very small, others are too low in grade."

The largest reserve base of lithium is in the Salar de Uyuni area of Bolivia, which has 5.4 million tonnes. Sony VAIO VGN-Z92YS Battery

US Geological Survey, estimates that in 2009 Chile had the largest reserves by far (7.5 million tonnes) and the highest annual production (7,400 tonnes). Other major suppliers include Australia, Argentina and China. Other estimates put Argentina's reserve base (7.52 million tonnes) above that of Chile (6 million).Sony VAIO VGN-Z93FS Battery

In June 2010, the New York Times reported that American geologists were conducting ground surveys on dry salt lakes in western Afghanistan believing that large deposits of lithium are located there. "Pentagon officials said that their initial analysis at one location in Ghazni Province showed the potential for lithium deposits as large of those of Bolivia, which now has the world's largest known lithium reserves." Sony VAIO VGN-Z93GS Battery

These estimates are "based principally on old data, which was gathered mainly by the Soviets during their occupation of Afghanistan from 1979–1989" and "Stephen Peters, the head of the USGS's Afghanistan Minerals Project, said that he was unaware of USGS involvement in any new surveying for minerals in Afghanistan in the past two years. Sony VAIO VGN-Z93HS Battery

'We are not aware of any discoveries of lithium,' he said."

Biological

Lithium is found in trace amount in numerous plants, plankton, and invertebrates, at concentrations of 69 to 5,760 parts per billion (ppb). Sony VAIO VGN-Z93VS Battery

In vertebrates the concentration is slightly lower, and nearly all vertebrate tissue and body fluids have been found to contain lithium ranging from 21 to 763 ppb.Marine organisms tend to bioaccumulate lithium more than terrestrial ones. It is not known whether lithium has a physiological role in any of these organisms,Sony A1258274A Battery

but nutritional studies in mammals have indicated its importance to health, leading to a suggestion that it be classed as an essential trace element with an RDA of 1 mg/day. Observational studies in Japan, reported in 2011, suggested that naturally occurring lithium in drinking water may increase human lifespan.Sony VGP-BPL10 Battery

History

Petalite (LiAlSi4O10) was discovered in 1800 by the Brazilian chemist José Bonifácio de Andrada e Silva in a mine on the island ofUtö, Sweden.However, it was not until 1817 that Johan August Arfwedson, then working in the laboratory of the chemistJöns Jakob Berzelius, detected the presence of a new element while analyzing petalite ore.Sony VGP-BPS10 Battery

This element formed compounds similar to those of sodium and potassium, though its carbonate and hydroxide were less soluble in water and morealkaline.Berzelius gave the alkaline material the name "lithion/lithina", from the Greek word ???o? (transliterated aslithos, meaning "stone"),Sony VGP-BPS10/S Battery

to reflect its discovery in a solid mineral, as opposed to potassium, which had been discovered in plant ashes, and sodium which was known partly for its high abundance in animal blood. He named the metal inside the material as "lithium".

Arfwedson later showed that this same element was present in the minerals spodumene and lepidolite.Sony VGP-BPS10A/B Battery

In 1818, Christian Gmelinwas the first to observe that lithium salts give a bright red color to flame.However, both Arfwedson and Gmelin tried and failed to isolate the pure element from its salts.It was not isolated until 1821, when William Thomas Brande obtained it by electrolysis of lithium oxide, a process that had previously been employed by the chemist Sir Humphry Davy to isolate the alkali metals potassium and sodium.Sony VGP-BPS10B Battery

Brande also described some pure salts of lithium, such as the chloride, and, estimating that lithia (lithium oxide) contained about 55% metal, estimated the atomic weight of lithium to be around 9.8 g/mol (modern value ~6.94 g/mol).In 1855, larger quantities of lithium were produced through the electrolysis of lithium chlorideby Robert Bunsen and Augustus Matthiessen.Sony VGP-BPS10A Battery

The discovery of this procedure henceforth led to commercial production of lithium, beginning in 1923, by the German company Metallgesellschaft AG, which performed an electrolysis of a liquid mixture of lithium chloride and potassium chloride.Sony VGP-BPS11 Battery

The production and use of lithium underwent several drastic changes in history. The first major application of lithium became high temperature grease for aircraft engines or similar applications in World War II and shortly after. This small market was supported by several small mining operations mostly in the United States. Sony VGP-BPL11 Battery

The demand for lithium increased dramatically during the Cold War with the production of nuclear fusion weapons. Both lithium-6 and lithium-7 produce tritium when irradiated by neutrons, and are thus useful for the production of tritium by itself, as well as a form of solid fusion fuel used inside hydrogen bombs in the form oflithium deuteride.Sony VGP-BPL12 Battery

The United States became the prime producer of lithium in the period between the late 1950s and the mid 1980s. At the end the stockpile of lithium was roughly 42,000 tonnes of lithium hydroxide. The stockpiled lithium was depleted in lithium-6 by 75%.Sony VGP-BPS12 Battery

Lithium was used to decrease the melting temperature of glass and to improve the melting behavior of aluminium oxide when using the Hall-Héroult process.These two uses dominated the market until the middle of the 1990s. After the end of the nuclear arms race the demand for lithium decreased and the sale of Department of Energy stockpiles on the open market further reduced prices.Sony VGP-BPL13 Battery

But in the mid-1990s, several companies started to extract lithium from brine which proved to be a less expensive method than underground or even open pit mining. Most of the mines closed or shifted their focus to other materials as only the ore from zoned pegmatites could be mined for a competitive price. Sony VGP-BPS13 Battery

For example, the US mines near Kings Mountain, North Carolina closed before the turn of the century. The use in lithium ion batteries increased the demand for lithium and became the dominant use in 2007. With the surge of lithium demand in batteries in to 2000s, new companies have expanded brine extraction efforts to meet the rising demand.Sony VGP-BPS13/B Battery

Production

Since the end of World War II lithium production has greatly increased. The metal is separated from other elements inigneous minerals such as those above. Lithium salts are extracted from the water of mineral springs, brine pools and brine deposits. Sony VGP-BPS13/S Battery

The metal is produced electrolytically from a mixture of fused lithium chloride and potassium chloride. In 1998 it was about 95 US$ / kg (or 43 US$/pound).

There are widespread hopes of using lithium ion batteries in electric vehicles,Sony VGP-BPS13/S Battery

but one study concluded that "realistically achievable lithium carbonate production will be sufficient for only a small fraction of future PHEV and EVglobal market requirements", that "demand from the portable electronics sector will absorb much of the planned production increases in the next decade", Sony VGP-BPS13A/B Battery

and that "mass production of lithium carbonate is not environmentally sound, it will cause irreparable ecological damage to ecosystems that should be protected and that LiIon propulsion is incompatible with the notion of the 'Green Car'".

Deposits of lithium are found in South America throughout the Andes mountain chain. Sony VGP-BPS13A/S Battery

Chile is the leading lithium producer, followed by Argentina. Both countries recover the lithium from brine pools. In the United States lithium is recovered from brine pools in Nevada. However, half the world's known reserves are located in Bolivia, a nation sitting along the central eastern slope of the Andes. Sony VGP-BPS13AS Battery

In 2009 Bolivia is negotiating with Japanese, French, and Korean firms to begin extraction. According to the US Geological Survey, Bolivia's Uyuni Desert has 5.4 million tonnes of lithium. China may emerge as a significant producer of brine-source lithium carbonate around 2010. Sony VGP-BPS13B/B Battery

There is potential production of up to 55,000 tonnes per year if projects in Qinghai province and Tibet proceed.

Worldwide reserves of lithium are estimated to be 23 million tonnes. Using the battery efficiency figure of 400 g of lithium per kWh, this gives a total maximum lithium battery capacity of 52 billion kWh which, assuming it is used exclusively for car batteries, is enough for approximately 2 billion cars with a 24 kWh battery (like a Nissan Leaf ).Sony VGP-BPS13B/Q Battery

Ceramics and glass

Lithium oxide is a widely used flux for processing silica, reducing the melting point and viscosity of the material and leading toglazes of improved physical properties including low coefficients for thermal expansion. Lithium oxides are a component of ovenware. Worldwide, this is the single largest use for lithium compounds (see chart).Sony VGP-BPS13B/S Battery

Electrical and electronics

In the later years of the 20th century lithium became important as an anode material. Used in lithium-ion batteries because of its high electrochemical potential, a typical cell can generate approximately 3 volts, compared with 2.1 volts for lead/acid or 1.5 volts for zinc-carbon cells. Sony VGP-BPS13Q Battery

Because of its low atomic mass, it also has a high charge- and power-to-weight ratio. Lithium batteries are disposable (primary) batteries with lithium or its compounds as an anode. Lithium batteries are not to be confused with lithium-ion batteries, which are high energy-density rechargeable batteries. Sony VGP-BPS13S Battery

Other rechargeable batteries include thelithium-ion polymer battery, lithium iron phosphate battery, and the nanowire battery. New technologies are constantly being announced.

Lubricating greases

The third most common use of lithium is in greases. Lithum hydroxide is a strong base, and when heated with a fat it produces a soap made of lithium stearate.Sony VGP-BPL7 Battery

Lithium soap has the ability to thicken oils, and it is used to manufacture all-purpose, high-temperature lubricating greases.

Inorganic lithium salts

Lithium chloride and lithium bromide are extremely hygroscopic and are used as desiccants.  Lithium hydroxide(LiOH) is an important compound of lithium obtained from lithium carbonate (Li2CO3).Sony VGP-BPS7 Battery

Metallic lithium and its complex hydrides, such as Li[AlH4], are used as high energy additives to rocket propellants.

Air purification

Lithium peroxide, lithium nitrate, lithium chlorate and lithium perchlorate are used as oxidizers in rocket propellants, and also in oxygen candlesthat supply submarines with oxygen.Sony VGP-BPL8 Battery

Lithium hydroxide and lithium peroxide are the salts most used in confined areas, such as aboard spacecraft and submarines, for carbon dioxide removal and air purification. Lithium hydroxide absorbs carbon dioxide from the air by reacting with it to form lithium carbonate, and is preferred over other alkaline hydroxides for its low weight. Sony VGP-BPL8A Battery

Lithium peroxide (Li2O2) in presence of moisture not only absorbs carbon dioxide to form lithium carbonate, but also releases oxygen. For example:

2 Li2O2 + 2 CO2 ? 2 Li2CO3 + O2.

Optics

Lithium fluoride, artificially grown as crystal, is clear and transparent and often used in specialist optics for IR, UV and VUV (vacuum UV) applications. Sony VGP-BPL8B Battery

It has one of the lowest refractive indexes and the farthest transmission range in the deep UV of most common materials.Finely divided lithium fluoride powder has been used for thermoluminescent radiation dosimetry (TLD): when a sample of such is exposed to radiation, it accumulates crystal defects which, Sony VGP-BPS8 Battery

when heated, resolve via a release of bluish light whose intensity is proportional to the absorbed dose, thus allowing this to be quantified. Lithium fluoride is sometimes used in focal lenses of telescopes.

The high non-linearity of lithium niobate also makes it useful in non-linear optics applications. Sony VGP-BPS8A Battery

It is used extensively in telecommunication products such as mobile phones and optical modulators, for such components as resonant crystals. Lithium applications are used in more than 60% of mobile phones.

Elemental lithium and reagents prepared from it

Because of its specific heat capacity, the highest of all solids, lithium metal is often used in coolants for heat transfer applications.Sony VGP-BPS8B Battery

The Mark 50 Torpedo stored chemical energy propulsion system (SCEPS) uses a small tank of sulfur hexafluoride gas which is sprayed over a block of solid lithium. The reaction generates enormous heat which is used to generate steam from seawater. The steam propels the torpedo in a closed Rankine cycle.Sony VGP-BPL9 Battery

When used as a flux for welding or soldering, metallic lithium promotes the fusing of metals during the process and eliminates the forming of oxides by absorbing impurities. Its fusing quality is also important as a flux for producing ceramics, enamels andglass.Sony VGP-BPS9 Battery

Alloys of the metal with aluminium, cadmium, copper and manganese are used to make high-performance aircraft parts (see also Lithium-aluminium alloys). Lithium compounds are also used as pyrotechnic colorants and oxidizers in red fireworks andflares.Sony VGP-BPS9/B Battery

Lithium metal is also used in the pharmaceutical and fine-chemical industry in the manufacture of organolithium reagents, which are used both as strong bases and as reagents for the formation of carbon-carbon bonds. Organolithium compounds are also used inpolymer synthesis as catalysts/initiators in anionic polymerization of unfunctionalized olefins.Sony VGP-BPS9/S Battery

Lithium is used in the preparation of organolithium compounds, which are in turn very reactive and are the basis of many synthetic applications.

Nuclear

Lithium-6 is valued as a source material for tritium production and as a neutron absorber in nuclear fusion. Sony VGP-BPS9A Battery

Natural lithium contains about 7.5% lithium-6 from which large amounts of lithium-6 have been produced by isotope separation for use in nuclear weapons. Lithium-7 gained interest for use in nuclear reactor coolants.

Lithium deuteride was the fusion fuel of choice in early versions of the hydrogen bomb. Sony VGP-BPS9A/B Battery

When bombarded by neutrons, both 6Li and7Li produce tritium—this reaction, which was not fully understood when hydrogen bombs were first tested, was responsible for the runaway yield of the Castle Bravo nuclear test. Tritium fuses with deuterium in a fusion reaction that is relatively easy to achieve. Sony VGP-BPS9A/S Battery

Although details remain secret, lithium-6 deuteride still apparently plays a role in modern nuclear weapons, as a fusion material.

Lithium fluoride as highly enriched in the lithium-7 isotope forms the basic constituent of the fluoride salt mixture LiF-BeF2that used in liquid-fluoride nuclear reactors.Sony VGP-BPS9B Battery

Lithium fluoride is exceptionally chemically stable and LiF-BeF2 mixtures have low melting points. In addition, 7Li, Be, and F are among the few nuclides with low enough thermal neutron capture cross-sections to not poison the fission reactions inside a nuclear fission reactor.Sony VGP-BPX11 Battery

In conceptualized nuclear fusion power plants, lithium will be used to produce tritium in magnetically confined reactors usingdeuterium and tritium as the fuel. Tritium does not occur naturally and will be produced by surrounding the reacting plasma with a 'blanket' containing lithium where neutrons from the deuterium-tritium reaction in the plasma will react with the lithium to produce more tritium.Sony VGP-BPL18 Battery

Lithium is also used as a source for alpha particles, or helium nuclei. When 7Li is bombarded by accelerated protons 8Be is formed, which undergoes fission to form two alpha particles. This feat, called "splitting the atom" at the time, was the first fully man-made nuclear reaction. It was produced by Cockroft and Walton in 1932.Sony VGP-BPS18 Battery

(Nuclear reactions and human-directed nuclear transmutation had been accomplished as early as 1917, but by using natural radioactive bombardment withalpha particles).

Medicine

In the treatment of bipolar disorder, lithium compounds continue to be the standard against which newer medications are measured.Sony VGP-BPL20 Battery

Lithium salts may also be helpful for related diagnoses, such as schizoaffective disorder and cyclic major depression. The active principle in these salts is the lithium ion Li+, although detailed mechanisms are debated.

Precautions

Lithium is corrosive and requires special handling to avoid skin contact. Sony VGP-BPS20/B Battery

Breathing lithium dust or lithium compounds (which are often alkaline) initially irritate the nose and throat, while higher exposure can cause a buildup of fluid in the lungs, leading to pulmonary edema. The metal itself is a handling hazard because of the caustic hydroxide produced when it is in contact with moisture. Sony VGP-BPS20/S Battery

Lithium is safely stored in non-reactive compounds such as naphtha.

There have been suggestions of increased risk of developing Ebstein's cardiac anomaly in infants born to women taking lithium during the first trimester of pregnancy.Sony VGP-BPL21 Battery

Regulation

Some jurisdictions limit the sale of lithium batteries, which are the most readily available source of lithium for ordinary consumers. Lithium can be used to reduce pseudoephedrine and ephedrine to methamphetamine in the Birch reduction method, which employs solutions of alkali metals dissolved in anhydrous ammonia.Sony VGP-BPS21 Battery

Carriage and shipment of some kinds of lithium batteries may be prohibited aboard certain types of transportation (particularly aircraft) because of the ability of most types of lithium batteries to fully discharge very rapidly when short-circuited, leading to overheating and possible explosion in a process called thermal runaway. Sony VGP-BPS21/S Battery

Most consumer lithium batteries have thermal overload protection built-in to prevent this type of incident, or their design inherently limits short-circuit currents. Internal shorts have been known to develop due to manufacturing defects or damage to batteries that can lead to spontaneous thermal runaway.Sony VGP-BPS21A Battery

A lithium-ion battery (sometimes Li-ion battery or LIB) is a family of rechargeable battery types in which lithium ions move from the negative electrode to the positive electrode during discharge, and back when charging. Chemistry, performance, cost, and safety characteristics vary across LIB types. Sony VGP-BPS21A/B Battery

Unlike lithium primary batteries (which are disposable), lithium-ionelectrochemical cells use an intercalated lithium compound as the electrode material instead of metallic lithium.

Lithium-ion batteries are common in consumer electronics. Sony VGP-BPS21B Battery

They are one of the most popular types of rechargeable battery forportable electronics, with one of the best energy densities, no memory effect, and a slow loss of charge when not in use. Beyond consumer electronics, LIBs are also growing in popularity for military, electric vehicle, and aerospaceapplications.Sony VGP-BPL22 Battery

Research is yielding a stream of improvements to traditional LIB technology, focusing on energy density, durability, cost, and intrinsic safety.

As of 2011, lithium-ion batteries account for 67% of all portable secondary battery sales in Japan.Sony VGP-BPS22 Battery

Charge and discharge

During discharge, lithium ions Li+ carry the current from the negative to the positive electrode, through the non-aqueous electrolyte and separator diaphragm.

During charging, an external electrical power source (the charging circuit) applies a higher voltage (but of the same polarity) than that produced by the battery, forcing the current to pass in the reverse direction.Sony VGP-BPS22/A Battery

The lithium ions then migrate from the positive to the negative electrode, where they become embedded in the porous electrode material in a process known as intercalation.

Construction

The three primary functional components of a lithium-ion battery are the anode, cathode, and electrolyte. Sony VGP-BPS22A Battery

The anode of a conventional lithium-ion cell is made from carbon, the cathode is a metal oxide, and the electrolyte is a lithium salt in anorganic solvent.

The most commercially popular anode material is graphite. The cathode is generally one of three materials: a layered oxide (such as lithium cobalt oxide), a polyanion (such as lithium iron phosphate), or a spinel (such as lithium manganese oxide). Sony VGP-BPL23 Battery

The electrolyte is typically a mixture of organic carbonates such as ethylene carbonate or diethyl carbonate containing complexesof lithium ions. These non-aqueous electrolytes generally use non-coordinating anion salts such as lithium hexafluorophosphate (LiPF6), lithium hexafluoroarsenate monohydrate (LiAsF6),Sony VGP-BPS23 Battery

lithium perchlorate (LiClO4), lithium tetrafluoroborate (LiBF4), and lithium triflate (LiCF3SO3).

Depending on materials choices, the voltage, capacity, life, and safety of a lithium-ion battery can change dramatically. Recently, novel architectures using nanotechnology have been employed to improve performance.Sony VGP-BPS23/B Battery

Pure lithium is very reactive. It reacts vigorously with water to form lithium hydroxide and hydrogen gas. Thus, a non-aqueous electrolyte is typically used, and a sealed container rigidly excludes water from

the battery pack.Sony VGP-BPS23/D Battery

Lithium ion batteries are more expensive than NiCd batteries but operate over a wider temperature range with higher energy densities, while being smaller and lighter. They are fragile and so need a protective circuit to limit peak voltages.Sony VGP-BPS23/G Battery

Formats

Li-ion cells are available in various formats, which can generally be divided into four groups:

  • Small cylindrical (solid body without terminals, such as those used in laptop batteries)
  • Large cylindrical (solid body with large threaded terminals)
  • Pouch (soft, flat body, such as those used in cell phones)   Sony VGP-BPS23/P Battery
  • Prismatic (semi-hard plastic case with large threaded terminals, often used in vehicles' traction packs)

The lack of case gives pouch cells the highest energy density; however, pouch cells (and prismatic cells) require an external means of containment to prevent expansion when their state-of-charge (SOC) level is high.Sony VGP-BPS23/W Battery

History

Lithium batteries were first proposed by M.S. Whittingham at Binghamton University, at Exxon, in the 1970s. Whittingham usedtitanium(II) sulfide as the cathode and lithium metal as the anode.Sony Limited Edition 007 Battery

The reversible intercalation in graphite and intercalation into cathodic oxides was also already discovered in the 1970s by J.O. Besenhard at TU Munich. He also proposed the application as high energy density lithium cells.

Primary lithium batteries in which the anode is made from metallic lithium pose safety issues. As a result, lithium-ion batteries were developed in which both anode and cathode are made of a material containing lithium ions.Sony VAIO VGC-LB15 Battery

In 1979, John Goodenough demonstrated a rechargeable cell with high cell voltage in the 4V range using lithium cobalt oxide(LiCoO2) as the positive electrode and lithium metal as the negative electrode. This innovation provided the positive electrode material which made LIBs possible. Sony VGN-AR Series Battery

LiCoO2 is a stable positive electrode material which acts as a donor of lithium ions, which means that it can be used with a negative electrode material other than lithium metal. By enabling the use of stable and easy-to-handle negative electrode materials, LiCoO2opened a whole new range of possibilities for novel rechargeable battery systems.Sony VGN-CR Series Battery

In 1981, Bell Labs developed a workable graphite anode to provide an alternative to the lithium metal battery.

In 1982, Rachid Yazami demonstrated the reversible electrochemical intercalation of lithium in graphite. Sony VIAO VGN-G Series Battery

The organic electrolytes available at the time would decompose during charging if used with a graphite negative electrode, preventing the early development of a rechargeable battery which employed the lithium/graphite system. Yazami used a solid electrolyte to demonstrate that lithium could be reversibly intercalated in graphite through an electrochemical mechanism.Sony VIAO VGN-G118 Battery

In 1983, Dr. Michael Thackeray, Goodenough, and coworkers identified manganese spinel as a cathode material. Spinel showed great promise, given its low-cost, good electronic and lithium ion conductivity, and three-dimensional structure, which gives it good structural stability. Sony VIAO VGN-G118CN/B Battery

Although pure manganese spinel fades with cycling, this can be overcome with chemical modification of the material. Manganese spinel is currently used in commercial cells.

In 1985, Akira Yoshino assembled a prototype cell using carbonaceous material into which lithium ions could be inserted as the anode, and as the cathode lithium cobalt oxide (LiCoO2), which is stable in air.Sony VIAO VGN-G118CN/T Battery

By using an anode material without metallic lithium, safety was dramatically improved over batteries which used lithium metal. The use of lithium cobalt oxide (LiCoO2) enabled industrial-scale production to be achieved easily.

This was the birth of the current lithium-ion battery.Sony VIAO VGN-G218 Battery

In 1991, Sony and Asahi Kasei released the first commercial lithium-ion battery.

In 1989, Goodenough and Arumugam Manthiram of the University of Texas at Austin showed that cathodes containing polyanions, e.g., sulfates, produce higher voltages than oxides due to the inductive effect of the polyanion.Sony VGN-TZ121 Battery

In 1996, Goodenough, Akshaya Padhi and coworkers identified lithium iron phosphate (LiFePO4) and other phospho-olivines (lithium metal phosphates with the same structure as mineral olivine) as cathode materials. Sony VGN-TZ13 Battery

In 2002, Yet-Ming Chiang and his group at MIT showed a substantial improvement in the performance of lithium batteries by boosting the material's conductivity bydoping it with aluminum, niobium and zirconium. The exact mechanism causing the increase became the subject of widespread debate.Sony VGN-TZ131 Battery

In 2004, Chiang again increased performance by utilizing iron phosphate particles of less than 100 nanometers in diameter. This decreased particle density almost one hundredfold, increased the cathode's surface area and improved capacity and performance.Sony VGN-TZ132N Battery

Commercialization led to a rapid growth in the market for higher capacity LIBs, as well as a patent infringement battle between Chiang and Goodenough.

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