Lithium is a metal element, known as green energy metal and "white"petroleum”, widely used inEnergy storage、chemical industry、medicine、metallurgy, electronic industry, etc.[1]Lithium is located in the second periodic IA group of the periodic table. The element symbol is Li. Its atomic number is 3, its atomic weight is 6.941, and its melting point is 180.5 ℃,boiling pointIt is 1342 ℃, the specific heat capacity is 3.58 kJ/kg · K, and the corresponding single substance is silver white soft metal, which has the lightest proportion among all known metals.[2]Reactive with water, soluble innitric acid、liquid ammoniaEtc.Lithium belongs toalkali metalHowever, its compounds are not as typical as other alkali metals, because lithium has a large and stable charge densityheliumType B double electron layer, which makes lithium easy to polarize othermoleculeOr ions, but they are not vulnerable topolarization。This will affect the stability of it and its compounds.[3]In addition, since the electrode potential of lithium is the most negativeradioactivityElement)Metal mobilityThe strongest.
Lithium has a very low density and can float on paraffin oil
In the 1890s, Jose Bonifacio de Andrada e Silva, a Brazilian chemical and politician, was found in a mine on Uto Island, SwedenLithium permeating feldspar（LiAlSifourOten）[5]。When he threw the ore into the fire, it would produce a strong crimson flame. However, he did not analyze the composition of the ore.It was not until 1817 when Johann Arfvedson analyzed the lithium permeable feldspar mineral in the laboratory of chemist J ö ns Jacob Berzelius that he found the existence of this new element, which he called lithium[6]。It comes from the Greek lithos, meaning "stone".The compound of this element is similar to that of sodium and potassium, but itscarbonateandhydroxideThe solubility in water is low, and the alkalinity is also low, so he realized that this is a new alkali metal element.However, he failed to separate it by electrolysis.In 1821, British chemist William Thomas Brande andDavidHumphry Davy uses the method of electrolytic lithium oxide to separate metal lithium, but this is not enough for experiment.By 1855, Robert Bunsen, a German chemist, and Augustus Matthiessen, a British chemist, were electrolyticlithium chlorideOnly then has obtained the massive lithium.[7]
Distribution in nature
Announce
edit
The main lithium minerals in nature arespodumene、lithia mica、Lithium permeating feldsparandPhosphoriteEtc;The liquid mineral containing lithium mainly includes salt lake brine, underground brine, hot spring, etc.In human and animal body, soil and mineral waterCocoa powderLithium can also be found in tobacco leaves and seaweed.[2]
according toUSGS(USGS) latest data statistics show that the global lithium resource reserves in 2022 will be about 26 million tonsLithium carbonateThe equivalent exceeds 130 million tons;Among them, the reserves of lithium resources in Chile rank first in the world, accounting for 35.8%, and the proven reserves are 9.3 million tons;Followed byAustralia、ArgentinaAnd China, with reserves of 6.2 million tons, 2.7 million tons and 2 million tons, accounting for 23.8%, 10.4% and 7.7% respectively.Lithium ore is highly concentrated in distribution areas, and the top five countries account for more than 80% of the world's reserves.[8]
Physical and chemical properties
Announce
edit
physical property
Lithium metal is a silvery white light metal, which is soft and can be cut with a knife.The melting point is 180.54 ℃, the boiling point is 1342 ℃, the density is 0.534 g/cm ³, the hardness is 0.6, and it is the lightest metal,densitySmaller than all oils and liquid hydrocarbons, lithium metal is soluble in liquid ammonia.Lithium has the smallest compressibility compared with other alkali metals because of its small atomic radius,hardnessmaximum,melting pointhighest.When the temperature is higher than - 117 ℃, the lithium metal is a typical body centered cubic structure, but when the temperature drops to - 201 ℃, it starts to transform intoFace centered cubic structureThe lower the temperature, the greater the transformation degree, but the transformation is incomplete.At 20 ℃, the lattice constant of lithium is 3.50 ∨,conductanceAbout one fifth of silver.[9]Lithium easily fuses with any metal other than iron.Lithium inFlame reactionIt is purple red in color.
There are seven lithiumisotope, of which two are stable, namelysixLi andsevenLi，In addition to being stable,half lifeThe longest one iseightLi，Its half-life is 838 milliseconds, followed bynineLi，The half-life of other isotopes is less than 8.6 milliseconds after 187.3 milliseconds.andfourLi is the isotope with the shortest half-life among all isotopes, only 7.58043 × 10-23second[10]。
sixLi has a strong ability to capture low-speed neutrons, which can be used to control the speed of nuclear reaction in uranium reactors, and can also prevent radiation and prolongNuclear missileIt will be used in nuclear powered aircraft and spacecraft in the future.sixLi is used in nuclear reactorsneutronIt can be obtained after irradiationtritiumAnd tritium can be used toThermonuclear reaction。sixLi can be used ascoolant。
chemical property
Electronic arrangement of lithium
When lithium is put into water, it will quickly react with water and release hydrogen, and can also quickly combine with oxygen and nitrogen in the air.Because of this, the storage of lithium is very troublesome, and can only be protected by solid paraffin or rare gas.When the temperature reaches above 100 ℃, lithium will burn in the air, showing a blue flame, which is very dangerous and generatesLithium oxide。The active nature of lithium enables it to react with most nonmetals except rare gases under certain conditions. It can also react with hydrogen,DeuteriumDeuterizationLithium hydride、Lithium deuterideAnd was used as the first one in ChinaHydrogen bomb。Because of its high charge density and stable helium type double electron layer, lithium is easy to polarize other molecules or ions, but not itself.This will affect the stability of it and its compounds.[25]
Lithium burns in air
Although the hydrogen standard of lithiumpotentialIt is the most negative, reaching -3.045V. However, since the solubility of lithium hydroxide is not large and the exothermic reaction of lithium with water cannot melt lithium, the reaction of lithium with water is not as intense as that of sodium. After a period of timenitrogen oxide The membrane is dissolved, making the reaction more intense.It is easy to react with hydrogen at about 500 ℃ to generate lithium hydride, which is the only alkali metal that can generate hydride stable enough to melt without decomposition, with ionization energy of 5.392eV, andoxygen、nitrogen、sulfurIsoenergetic combination is the only reaction with nitrogen at room temperature to generateLithium nitrideAlkali metal of (Li ∨ N).Darkening due to susceptibility to oxidation.If lithium is thrown intoconcentrated sulfuric acid, then it will float quickly on sulfuric acid, burn and explode.If lithium andPotassium chlorateWhen mixing (shock or grinding), it may also produce explosive reaction.Lithium hydride reacts violently with water to produce a large amount of hydrogen.
Some chemical reaction equations related to lithium:
Because the atomic weight of lithium is very small,Electrode potentialLow, so the battery with lithium as negative electrode has highenergy density 。In addition, lithium batteries have many advantages, such as light weight, small size, long life, good performance, low pollution, and so on.Before the development of power batteries, lithium was mainly used in traditional industries. In 2010, lithium batteries accounted for 27% of downstream demand,grease, ceramics and other traditional industries accounted for 73% of the demand;With the vigorous development of the consumer electronics and electric vehicle industries, the battery industry has occupied more than 78% of the market share in the consumption structure in 2021, becoming the most important application field.[11]Now, lithium batteries have been widely used in electric vehicles, energy storage batteries, laptops, mobile phones, digital cameras, small electronic equipment, aerospace, electromechanical, military communications and other fields.
reducing agent
Lithium metal is soluble in liquid ammonia andethanolA good reducing agent is formed in the mixed solvent ofAromatic ringOrganic compounds.Valuable steroids are usually reduced in this way.The advantage of this method is that the yield is high, but the disadvantage is that it is more expensive than sodium reduction, so it is only used to reduce some valuable compounds.
catalyzer
Lithium containing compounds can be used as organic reaction catalysts, such asbutadiene、isopreneetc.DienePolymerization can also be used for manufacturingcopolymer[12]。
2. Lithium alcohol catalyst: such as lithium alcohol compound, commonly used inaldehydeandketoneSelective hydrogenation reaction.
3. Lithium salt catalysts: including lithium halides and lithium alkali metal compounds, commonly used in organic synthesis of Bentokama andFluorination reaction。
4. Lithium hydrocarbon catalyst: such asBuli andIsobutyllithium solution , commonly used in lithiation and metal based organic reactions, such as the synthesis of organic lithium reagents and the initial step of organic synthesis reaction.
Metallurgical industry
As a component of light alloy, ultra light alloy, wear-resistant alloy and other nonferrous alloys, lithium can greatly improve the properties of alloys.For example, lithium magnesiumalloyIt is a high-strength light alloy, which not only has good heat conduction, conductivity and ductility, but also has the characteristics of corrosion resistance, abrasion resistance, good impact resistance, and resistance to high-speed particle penetration. It is known as the "aerospace alloy of tomorrow" and is widely used in aerospace, national defense and military industry and other fields.With the increasing requirements of the world for lightweight structural materials, weight reduction and energy saving, environmental protection and sustainable development, magnesium lithium alloys will also be used in transportation, electronics, medical products and other fields that need lightweight structural materials.[13]
Lithium is also effectiveDegasifier。Because of its strong chemical activity, when lithium is added to a molten metal or alloy, it will react with gases such as hydrogen, oxygen, sulfur and nitrogen in the metal or alloy to form compounds with low density and low melting point, which can not only remove these gases, make the metal more compact, but also eliminate bubbles and other defects in the metal, thus improving the crystal structure of the metal,MetallicMechanical properties。
Space fuel
Lithium and its compounds have the characteristics of high combustion degree, fast speed, wide flame and high heat value.The energy released by 1kg lithium through thermonuclear reaction is equivalent to the combustion of more than 20000 tons of high-quality coal[26]。Therefore, lithium is one of the best metals used as rocket fuel.If lithium or lithium compounds are used to make solid fuels insteadsolid propellantAs the driving force of rockets, missiles and spaceshipsSpecific impulse, the effectiveness of rocketsloadIt directly depends on the specific impulse.
Glass industry
If lithium is added in glass manufacturing, the solubility of lithium glass is only 1/100 of ordinary glass (about one ten thousandth of a gram of glass in each ordinary glass cup of hot tea). After adding lithium, the glass becomes "insoluble" and can resist acid corrosion.Lithium concentrateOr lithium compounds have a greater melting aid role in the manufacture of glass, and can reduce the temperature of glass melting and the melt temperatureviscositySimplify production process, reduce energy consumption, extend furnace life, increase output, improve operating conditions and reduce pollution.In addition, adding lithium compounds in glass can also reduce the coefficient of thermal expansion of glass, improve the density and smoothness of glass, and improve the strength, ductility, corrosion resistance and thermal shock resistance of products.Lithium containing glass is now widely usedChemistry、electronics、opticsAnd modern science and technology departments, and even used in daily necessities.[14]
Grease industry
Compared with potassium, sodium and calcium based grease, lithium based grease has the advantages of oxygen resistance, pressure resistance and good lubrication performance. In particular, lithium based grease has a wide working range and good water resistance. It hardly changes the viscosity of grease at - 60 ℃~300 ℃. It can maintain good stability even when the amount of water is small, so it is applied to aircraft, tanks, trains, automobilesmetallurgy、petrochemical industry、Radio detectionAnd other equipment.[15]
Medical field
Lithium is also widely used in the medical field, and its beneficial effects on the human body include the treatment of manic depressive disorder, prevention of cognitive degradation, anti-inflammatory effect, and impact on cardiovascular health.
1. Treatment of manic depressive disorder: lithium salt is a treatmentManic depressive disorderIt is a common drug for relieving symptoms, such as mood fluctuation, insomnia, anxiety, etc.
2. Prevention of cognitive degradation: research shows that lithium salt can help prevent cognitive degradation andAlzheimer diseaseAnd other neurodegenerative diseases.
3. Anti inflammatory effect: Lithium can inhibit inflammation and alleviate some symptoms of inflammatory diseases.
4. Impact on cardiovascular health: lithium can reduce blood pressure, improve heart health and prevent cardiovascular diseases.[16]
It should be noted that lithium salt has side effects, such as thirst, polyuria, kidney damage, etc. It should be used under the guidance of a doctor.
Other applications
Lithium metal has the properties of large heat capacity, wide range of liquid temperature, high thermal conductivity, low viscosity and low density, and is used as coolant in nuclear fusion or fission reactors.
Lithium bromide is an efficient water vapor absorber and air humidity regulator, which is widely used in air conditioning, dehumidification, refrigeration andAir purificationSystem.
Lithium can also be used to produce "lithium fertilizer" to prevent tomato decay and wheat rust head disease.
Adding lithium salt in aluminum reduction cell can improve the fluidity of molten salt, reduce the electrolysis degree and save electric energy significantly.
N-butyl lithium is also used for synthesisstyrene , ButadienolInitiatorIt is widely used in high temperature and low temperature resistant rubber sealing materials and rubber tires. The service life of rubber tires can be increased by more than four times by adding butyl lithium.
Lithium fluorideyesultraviolet raysIt has extremely high transparency, and the glass made with it can penetrate into the hiddenGalaxyThe deepest mystery.Lithium glass can be used to make TV picture tubes.
Instead of deuterium and tritium, lithium deuteride and lithium tritide are used as explosives in hydrogen bombs to achieve the purpose of hydrogen bomb explosion.Lithium deuteride was used in the first hydrogen bomb successfully exploded in China on June 17, 1967.
Lithium borohydrideandLithium aluminum hydrideIt is widely used as reducing agent in organic chemical reactions. Lithium borohydride can reduce aldehydes, ketones and esters.
Lithium aluminum hydride is an important reducing agent in the preparation of drugs, spices and fine organic chemicals.Lithium aluminum hydride can also be used as jet fuel.Lithium aluminum hydride is a strong reducing agent for special bonding of complex molecules, which has become an important reagent in many organic synthesis.
Organic lithium compounds react with organic acids to obtain energyhydrolysisThe addition product of ketone formation, which is used forvitamin AOne step of synthesis.Organic lithium compounds are added to aldehydes and ketones to obtain an addition product that can produce alcohol during hydrolysis.
Lithium can be used as the red part of fireworks.
Lithium amine, prepared by the reaction of lithium and ammonia, is used to introduce amino groups, and is also used as a dehalogenation reagent and catalyst.
In September 2022, scientists from Harvard University developed a new solid state lithium metal battery for electric vehicles (EVs).This battery uses pure metal lithium, which is expected to be fully charged within 3 minutes.[17]
Security risk
Announce
edit
toxicity
Lithium and its compounds can be used to treat some diseases such as seborrheic dermatitis and manic depressive disorder, but excessive use will causeCentral nervous systemSystemic poisoning and renal failure. The precursor of poisoning is dullness, fatigue, lethargy, muscle twitching, unclear words, decreased appetite, vomiting and diarrhea, etc. At the same time, oral lithium containing drugs may also worsen existing skin diseases.[18-19]
At present, there is no specific antidote for lithium poisoning. The main treatment is to keep breathing unobstructed and prevent respiratory tract infection.No addiction to lithium poisoning has been found, and no sequelae have been observed after stopping taking lithium drugs.
danger
Like other alkali metals, it is highly corrosive, causing irritation or burns due to eye and skin contact, lithiumSimple substanceThe chemical property of lithium is very active. It reacts violently with halogen. Lithium reacts with water to release hydrogen.When heated to the molten state, it can spontaneously ignite in the air, and may explode when heated under certain conditions.[20]
First aid measures
First aid measures
Contact part
First aid measures
Skin contact
In case of skin contact with lithium metal, please immediately take off the contaminated clothes and wash with flowing water. If the contact part still feels uncomfortable, please go to the hospital immediately
Eye contact
Immediately lift the eyelid, and thoroughly flush it with a large amount of flowing water or physiological saline for at least 15 minutes.Get medical attention.
Ingestion
If you accidentally ingest lithium metal, please rinse your mouth and drink milk or egg white immediately, and then go to the hospital for medical treatment.[20]
Fire fighting measures
In case of fire caused by lithium, use sodium carbonate dry powder or drygraphiteThe powder insulates the air and water mist, and smoulders the flame.Do not use straight water, foam orhalideDirect flow water may cause splashing of combustible liquid and thus spread the fire.[21]
Storage method
Announce
edit
Lithium has active chemical properties, so we should pay attention to safety in its storage and use.Normally, lithium metal does not react with oxygen in a dry environment, but reacts with oxygen in a humid environment. The color will change from silver white to black and then to white. Lithium metal is generally stored in a dry laboratoryinert gasEnvironment orparaffin waxMedium.[20]
Production process
Announce
edit
Production process of lithium
Electrolytic method
Guntz first suggested electrolysismeltlithium chlorideandpotassium chlorideTo prepare lithium metal, and place anhydrous lithium chlorideElectrolytic cellUsing anhydrous potassium chloride as assistant, lithium metal is prepared by melting and electrolysis at high temperature.[22]Liquid metal lithium precipitates at the cathode and accumulates on the surface of molten salt. Domestic manufacturers use metal ladles to scoop out metal lithium from the electrolytic cell, pour it into transformer oil for cooling and ingot casting.
Li+e‒→Li
2Cl‒→Cltwo+2e‒
2LiCl(l)→2Li(s)+Cltwo(g)↑
The metallic lithium produced by electrolysis usually has mechanical impurities such as Na, K, Mg, Ca, Fe, Si and Al, which must be purified;Impurities can be remelted and filtered with different specific gravity. The sodium and potassium that are difficult to remove can be removed by hydrogenation.
Thermal reduction
3LitwoO＋2Al→6Li＋AltwoOthree
2LitwoO＋Si→4Li＋SiOtwo
Reduced lithium oxide isEndothermic reactionIn addition, lithium metal is very active and can only react at high temperature and high vacuum.
Extraction method of lithium ore
Sulfuric acid process
spodumeneandpotassium sulphateTogethersinter, potassium will be lithiumsubstitutionCome out to form water solubleLithium sulfate。Sulfate decomposition is the only method for industrial preparation of lithium for a long time.This method is not only applicable to spodumene, but also can be used to treatlithia mica。
The key problem of this reaction is that sulfuric acid can onlyβ-Spodumene reaction, while forα-Spodumene cannot react with it.The lithium extracted from the calcined spodumene directly decomposed by sulfuric acid only accounts for 4% of the total amount.[24]
Lime method
Put lime orlimestoneAndLithium oreSinter together, and then treat with water. The leaching solution can crystallize from it after multiple evaporationLithium hydroxide, the reaction formula is as follows (temperature is 1000 ℃):
It has strong applicability and can decompose almost all lithium ores.
The reaction does not require scarce raw materials, and lime and limestone are cheap and easy to obtain.
Disadvantages:
The concentrate will be depleted during sintering, and the lithium content in the concentrate is required to be very high.
Dilute solution is obtained after leaching,evaporationIt consumes a lot of heat and takes a long time.
Extraction of lithium from natural brine
The source of lithium also includes naturalbrineAnd some salt lake water, the extraction technology mainly focuses onadsorbentLawMembrane separationLawextractionIn the technical direction of precipitation methodelectrochemistryLawdialysisLawcrystalLawIon exchangeLaw also has a certain R&D layout;In addition, the characteristics of technology fusion and combination application of various technology and process routes are obvious.[23]
