- Lithium (Li) is the third lightest element and the lightest of all metals, with atomic number 3 and belonging to Group 1 of the periodic table, known as the alkali metals.
- Its atomic structure consists of three protons, usually three or four neutrons, and three electrons arranged in two shells (two in the inner shell and one in the outer shell). This single valence electron gives lithium its characteristic high reactivity and metallic properties, although it is less reactive than heavier alkali metals such as sodium and potassium.
- In pure form, lithium is a soft, silvery-white metal that tarnishes quickly in moist air due to the formation of lithium oxide or hydroxide. It has the lowest density of all solid elements, allowing it to float on water, and it is highly flammable, especially in finely divided form.
- Lithium has two stable isotopes: lithium-6 (⁶Li) and lithium-7 (⁷Li), with lithium-7 being far more abundant in nature.
- In the universe, lithium is relatively rare compared to hydrogen and helium, even though it is one of the few elements believed to have been produced during Big Bang nucleosynthesis. Much of the primordial lithium has been destroyed over cosmic time through nuclear processes inside stars, making it less common in stellar and interstellar environments.
- On Earth, lithium does not occur in its elemental metallic form due to its reactivity; instead, it is found in various mineral ores such as spodumene, petalite, and lepidolite, as well as in brine pools and certain clays.
- Large lithium deposits are found in countries like Australia, Chile, Argentina, and China, with the “Lithium Triangle” in South America being a key global supplier.
- Extraction methods typically involve either mining mineral ores or evaporating lithium-rich brines to produce lithium carbonate or lithium hydroxide.
- The discovery of lithium dates back to 1817, when Swedish chemist Johan August Arfvedson identified it while analyzing the mineral petalite. Although Arfvedson could not isolate pure lithium, his work revealed the presence of a new element. In 1821, English chemist William Thomas Brande and physicist Sir Humphry Davy independently produced small amounts of metallic lithium through the electrolysis of lithium oxide.
- The name “lithium” derives from the Greek word lithos (stone), reflecting its occurrence in mineral form rather than in plants or animals, which was unusual for alkali metals at the time.
- Lithium’s modern importance has grown exponentially, especially in the fields of energy storage and advanced technology.
- Lithium-ion batteries, first commercialized in the early 1990s, are now ubiquitous in portable electronics, electric vehicles, and renewable energy storage systems due to their high energy density, lightweight nature, and rechargeability.
- Lithium compounds also have significant uses beyond batteries: lithium carbonate and lithium citrate are used in psychiatric medicine as mood stabilizers, particularly for the treatment of bipolar disorder; lithium stearate serves as a high-temperature lubricant; and lithium metal alloys are employed in aerospace applications to reduce weight.
- Additionally, lithium deuteride is a key material in thermonuclear fusion devices, serving as a fusion fuel in hydrogen bombs.
- From a physical and chemical standpoint, lithium’s combination of low atomic mass, high electrochemical potential, and strong heat capacity makes it both scientifically intriguing and technologically invaluable. However, the rapid rise in demand for lithium has raised environmental and geopolitical concerns. Extraction from brine fields can consume large amounts of water, impacting local ecosystems and communities, particularly in arid regions.
- As the transition to green energy accelerates, sustainable lithium sourcing, recycling of spent batteries, and development of alternative chemistries are becoming increasingly important for the future stability of its supply.
