Lithium

• 1. Introduction

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  Lithium, the element with atomic number 3, is soft enough to cut with a knife and light enough to float on water. Its density is just 0.534 grams per cubic centimeter, the lowest of any metal under ordinary conditions. Only sodium and potassium share its ability to ride on water's surface. Even the oil used to protect it from air cannot hold it down, because the metal is too light to sink fully into it. Left in open air, its silvery shine fades to gray and then black. In nature it never appears as a pure metal. So why is an element this light so scarce across the universe? Who named it, and what does the name mean? How did it end up in hydrogen bombs, aircraft grease and the treatment of mental illness? And who pays when the world goes looking for more of it?

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• 2. Naming The Stone

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  In 1800, the Brazilian chemist and statesman José Bonifácio de Andrada e Silva found a mineral called petalite in a mine on the Swedish island of Utö. The new element hiding inside it was not detected until 1817. That year, Johan August Arfwedson was working in the laboratory of Jöns Jakob Berzelius and analyzed petalite ore. He noticed a substance that behaved much like sodium and potassium. Its carbonate and hydroxide, however, dissolved less readily in water and were less alkaline.

  Berzelius took the name from the Greek word lithos, meaning stone. The choice marked a contrast. Potassium had first turned up in plant ashes, and sodium was known partly for its abundance in animal blood. This material had come out of solid rock. He called the alkaline substance lithion, or lithina, and the element itself lithium.

  Arfwedson went on to find the same element in the minerals spodumene and lepidolite. In 1818, Christian Gmelin became the first to see that lithium salts turn a flame bright red. Both men tried to isolate the pure metal, and both failed.

  The breakthrough came in 1821, when William Thomas Brande used electrolysis on lithium oxide. Sir Humphry Davy had already used that technique to isolate potassium and sodium. Brande also described pure salts such as the chloride. He reckoned that lithia was about 55% metal, which gave him an atomic weight near 9.8 grams per mole. The modern value is about 6.94.

  In 1855, Robert Bunsen and Augustus Matthiessen produced larger quantities by electrolyzing lithium chloride. Their method opened the way to commercial production in 1923 by the German company Metallgesellschaft AG, which worked with a molten mixture of lithium chloride and potassium chloride.

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• 3. Cosmic Rarity

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  Lithium-7 formed very early in the history of the universe, during a process called Big Bang nucleosynthesis. Only a small amount appeared, far less than hydrogen or helium. Beryllium-7 was made too, and it later decayed into more lithium-7. Measurements of primordial lithium do not match the model, a mismatch called the cosmological lithium problem. Nobody knows whether the fault lies in the difficult measurements or in the theory itself. Lithium-7 can be created and destroyed in cosmic ray collisions, novae, supernovae and the interiors of stars, which clouds the picture. The only known way to make lithium-6 is through cosmic-ray interactions.

  Lithium is rarer in the Solar System than 28 of the first 34 elements, despite having very light nuclei. That makes it an exception to the usual trend that heavier nuclei are scarcer. The cause is a nucleus that verges on instability. Its two stable isotopes, lithium-6 and lithium-7, have unusually low binding energy per nucleon. Among stable nuclides, only hydrogen-1, deuterium and helium-3 are bound more loosely. Lithium-7 accounts for 95.15% of natural lithium.

  The unstable isotopes show how fragile this nucleus can be. Seven radioisotopes have been characterized. The longest-lived, lithium-8, has a half-life of 838 milliseconds. The shortest-lived, lithium-4, sheds a proton with a half-life of 7.6 times ten to the minus 23 seconds. The exotic lithium-11 carries a neutron halo, with two neutrons orbiting a core of 3 protons and 6 neutrons.

  Brown dwarfs give astronomers a practical use for the element. Lithium survives in cooler, less massive brown dwarfs but is destroyed in hotter red dwarf stars. Spotting it in a spectrum therefore separates the two, in what is called the lithium test. Certain red giants also hold a lot of lithium, and one proposed explanation is that they pull it from a companion star. The same loosely bound nuclei would soon make lithium valuable to physicists and weapon designers.

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• 4. Nuclear Years

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  In 1932, Cockcroft and Walton bombarded lithium-7 with accelerated protons and formed beryllium-8. That nucleus almost immediately broke into two alpha particles. At the time it was described as "splitting the atom," and it was the first fully human-made nuclear reaction.

  During the Cold War, demand for lithium rose dramatically. Both lithium-6 and lithium-7 produce tritium when struck by neutrons. Lithium deuteride therefore became the fusion fuel of choice in early hydrogen bombs. Designers had not fully understood this reaction when hydrogen bombs were first tested. It was responsible for the runaway yield of the Castle Bravo test. Details remain secret, but lithium-6 deuteride apparently still plays a role in modern weapons.

  Between the late 1950s and the mid-1980s, the United States was the leading producer. Its stockpile ended up at roughly 42,000 tonnes of lithium hydroxide, with lithium-6 depleted by 75%. That was enough to shift the measured atomic weight of lithium in many standard chemicals. Lithium salts discharged from isotope separation facilities even reached groundwater, which altered some supposedly natural samples.

  Future fusion power plants, if they are ever built, would depend on lithium as well. A blanket of lithium around the plasma would breed new tritium, because naturally occurring tritium is extremely rare.

  In 1963, the United States shut down most of its isotope separation machinery, since it held a huge surplus of separated lithium. That decision caught up with civilian power decades later. In 2013, the US Government Accountability Office warned that a shortage of lithium-7 put 65 of 100 American reactors at some risk. Those reactors use lithium-7 to counter the corrosive effects of boric acid, which is added to the water to absorb excess neutrons. The report estimated that rebuilding the lost capacity would take five years and 10 to 12 million dollars.

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• 5. A Mood Stabilizer

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  In 1949, the Australian psychiatrist John Cade was credited with reintroducing lithium as a treatment for mania. From the 1950s, Mogens Schou of Denmark carried the research forward. Through the middle of the twentieth century, lithium's use against mania and depression took off in Europe and the United States. An element cannot be patented, so the medicine was developed by academia rather than by drug companies.

  Today lithium carbonate is classed as a mood stabilizer and sits on the World Health Organization's List of Essential Medicines. The active part of these salts is the lithium ion. It works as a maintenance treatment for bipolar disorder and is especially useful against mania. It may also help in related diagnoses such as schizoaffective disorder and cyclic major depressive disorder.

  The risks are real. Infants born to women who take lithium during the first trimester may face a higher chance of Ebstein's cardiac anomaly. Too much lithium leads to lithium toxicity.

  Studies spanning 40 years, including several randomized controlled trials, show that lithium is highly effective at reducing suicide among people with mood disorders. It also lowers death from all causes in these patients. Reduced suicide has been correlated with lithium even at very low doses. Trace amounts in the water supply have been associated with a lower risk of suicide, homicide, rape, drug arrests and other crimes.

  How it works is only partly understood. Human tissue averages about 24 parts per billion of lithium, with 4 in blood and 1.3 parts per million in bone. Whether lithium has a physiological role in any living thing is unknown. Its ion competes with sodium and with magnesium, whose ionic radius of 86 picometers is close to lithium's 90. Sodium channels are a major route into cells for lithium. In patients with bipolar disorder, lithium partially reverses telomere shortening and increases mitochondrial function, though nobody has explained how.

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• 6. Greases To Batteries

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  Aircraft engines of World War II were among the first big customers for lithium. Lithium-based soaps melt at higher temperatures than other alkali soaps and corrode less than calcium-based ones. A handful of small mines, mostly in the United States, met that modest demand. Greases remain the third most common use today. Heating lithium hydroxide with a fat such as stearic acid yields lithium stearate, a soap that thickens oils into all-purpose, high-temperature grease.

  Glass and ceramics came next. Lithium oxide acts as a flux for silica, lowering its melting point and viscosity and producing glazes used on ovenware. This is the second largest use of lithium compounds. In aluminium smelting, lithium fluoride lowers the melting temperature in the Hall-Héroult process. Glass and aluminium dominated the market until the middle of the 1990s.

  When the nuclear arms race ended, demand fell. Sales of Department of Energy stockpiles on the open market pushed prices lower still. In the mid-1990s, several companies began isolating lithium from brine, which proved cheaper than mining. Most mines closed or changed focus. The mines near Kings Mountain, North Carolina, shut before the 21st century began.

  Batteries then took over. Lithium-ion batteries became the dominant use in 2007, and by 2021 they absorbed 87% of world production, mostly for electric cars and mobile devices. Lithium offers a high electrode potential and a low atomic mass, so it stores a lot of charge for its weight. A typical lithium-ion cell produces about 3 volts, against 2.1 for lead-acid and 1.5 for zinc-carbon. Unlike disposable lithium metal batteries, lithium-ion cells can be recharged.

  Smaller jobs abound. Lithium hydroxide scrubs carbon dioxide from the air aboard spacecraft and submarines, and it is preferred for its low weight. Lithium peroxide also releases oxygen. Lithium compounds color fireworks and flares red. Lithium niobate serves in resonant crystals, and lithium applications appear in more than 60% of mobile phones. The Mark 50 torpedo sprays sulfur hexafluoride over a block of solid lithium, and the heat makes steam that drives it.

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• 7. Salt Flats And Rock

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  The oceans hold an estimated 230 billion tonnes of lithium, yet it is spread thin at only 0.14 to 0.25 parts per million. The Earth's crust holds 20 milligrams per kilogram, which makes lithium the 31st most abundant element. Many deposits exist, but few are worth working, because most are small or too low in grade.

  In pegmatites, the story begins with the lithium ion's small size. It fits poorly into early crystals, so it stays in the molten rock and grows richer until the final stage of solidification. That enrichment is behind every commercially promising ore deposit. Spodumene and petalite are the most viable minerals.

  Chile, Bolivia and Argentina share the Lithium Triangle, home to the salt flats of Salar de Uyuni, Salar de Atacama and Salar de Arizaro. It was once estimated to hold over 75% of the lithium reserves then known. Bolivia's Uyuni area has 5.4 million tonnes. By 2022, the Bolivian government had invested US$900 million, and in 2021 it produced 540 tons.

  In Chile's Salar de Atacama, solar evaporation ponds raise the brine to 6% lithium over as long as a year and a half. Final processing happens near the coastal city of Antofagasta, at Salar del Carmen and La Negra. There the plants turn out lithium carbonate, hydroxide and chloride.

  Australia led output in 2023 with 91,700 tonnes, out of a world total of 204,000 tonnes according to the US Geological Survey. Much of it comes from hard rock, including the Greenbushes pegmatite, where the Talison mine was reported in 2012 to have ore grading 2.4% lithium oxide.

  New finds keep arriving. Since 2018, the Manono deposit in the Democratic Republic of Congo has been known as the largest spodumene hard-rock deposit, possibly holding up to 1.5 billion tons. In 2025, a deposit of lithium brines equal to 43 million tons of lithium carbonate was found in the Altmark region of Saxony-Anhalt, Germany. In 2010, American geologists surveyed dry salt lakes in western Afghanistan, working from old Soviet data gathered in 1979-1989. The Department of Defense called the country a potential "Saudi-Arabia of lithium."

  Lithium carbonate sold for around $10,000 per ton in 2024. Some argue the metal will be a prime object of geopolitical competition. Critics reply that this view underestimates the power of economic incentives to expand production.

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• 8. The Cost Of Extraction

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  Evaporating brine in dry country takes about 1.9 million liters of water for every ton of lithium, a heavy burden in places like northwestern Argentina. In the Puna region in 2023, two companies, Minera Exar and Sales de Jujuy, extracted over 3.7 billion liters of fresh water. That was more than 31 times the annual water use of the local community in Susques department. Reporting on Argentina also found that companies generally controlled community access to information and set the terms for discussing benefit sharing.

  In Chile's Salar de Atacama, the Likan Antay people have both opposed lithium extraction and bargained for shared benefits. One commentator argues that agreements with companies brought significant economic resources but also widened the industry's capacity for social control. In 2024, Albemarle Limitada reached a conciliatory agreement to make reparations for freshwater uptake that, along with copper mining, would have helped dry out meadows on traditional Atacameño lands. The company says its own use is small compared with that of the neighboring copper miners.

  Wildlife is at risk too. The Andean flamingo and a small fish known locally as karachi, Orestias parinacotensis, live around the salt lakes of the Lithium Triangle and are especially threatened by the damage.

  Resistance has spread well beyond South America. In 2021, mass protests broke out in Serbia against a lithium mine planned in the west of the country by the Rio Tinto corporation. In 2024, an EU-backed project there set off large protests again. In Nevada, several indigenous tribes have sued over the Thacker Pass mine, saying they never gave free prior and informed consent. Protestors have occupied the site since January 2021. In Zimbabwe, a surge in lithium prices in the early 2020s brought a "lithium fever" of displacement and clashes between artisanal miners and large companies.

  Engineers hope to ease the strain with Direct Lithium Extraction, which skips evaporation. A 2020 proposal would draw lithium from seawater, which holds it at about 0.2 parts per million. In 2024, a redox and electrodialysis system was claimed to promise enormous cost savings, shorter timelines and less environmental damage than evaporation ponds.

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