Physical world and mathematics

Lithium brines

Lithium brines are lithium-rich saline groundwaters beneath dry salt flats and salt lakes, pumped and concentrated in evaporation ponds; they supply about three-fourths of world lithium production.

Lithium bromide

Lithium bromide (LiBr) is a highly hygroscopic white crystalline salt of lithium and bromine, the standard absorbent in water/LiBr absorption chillers and heat pumps since the 1950s.

Lithium burning

Lithium burning is the nuclear destruction of lithium inside stars, which begins at about 2.5 million K and makes surface lithium a clock for dating young stars and clusters.

Lithium carbonate

Lithium carbonate (Li2CO3) is the lithium salt of carbonic acid, a white powder that is the main commercial form of lithium and the mood-stabilizing drug for bipolar I disorder.

Lithium chloride

Lithium chloride (LiCl) is a white, extremely hygroscopic lithium salt used as a liquid desiccant in air conditioning, a flux for welding aluminum, and a selective precipitant of RNA.

The lithium depletion boundary is a method for dating young star clusters and associations by finding the mass at which members have burned their lithium, reliable from about 20 to a few hundred million years.

Lithium diisopropylamide

Lithium diisopropylamide (LDA) is a strong, sterically hindered, non-nucleophilic base with formula C6H14LiN, used for 50 years in organic synthesis to form lithium enolates of ketones, aldehydes, and esters.

Lithium disilicate

Lithium disilicate (Li2Si2O5) is a glass-ceramic of interlocking needle-like crystals in a glass matrix, the most widely used high-strength dental ceramic, sold as IPS e.max.

Lithium fluoride

Lithium fluoride (LiF) is an inorganic salt of lithium and fluorine that forms transparent cubic crystals and is used in ultraviolet optics, radiation dosimetry, and batteries.

Lithium hydride

Lithium hydride (LiH) is an ionic compound of lithium and hydrogen that reacts violently with water and serves as a reducing agent and neutron-shielding material.

Lithium hydride-mediated chemical looping ammonia synthesis

Lithium hydride-mediated chemical looping ammonia synthesis is a two-step route in which LiH fixes nitrogen as Li2NH, then releases NH3 on hydrogenation, avoiding Haber–Bosch conditions.

Lithium hydroxide

Lithium hydroxide (LiOH) is a white hygroscopic solid, the strongest alkali-metal hydroxide in commercial use, serving as a carbon dioxide scrubber in spacecraft and a battery cathode precursor.

Lithium iridate

Lithium iridate (Li2IrO3) is an iridium oxide with layered honeycomb-type magnetic lattices of Ir4+ ions, studied as a realization of the Kitaev model and unusual for existing in three polymorphs, alpha, beta, and gamma.

Lithium manganese oxide

Lithium manganese oxide (LMO) is a spinel cathode material, LiMn2O4, for lithium-ion batteries, first reported in 1983 and used in power tools and early EVs.

Lithium nickel cobalt aluminium oxides

Lithium nickel cobalt aluminium oxides, abbreviated NCA, are layered lithium-ion battery cathode materials with capacity of 180–200 mAh/g, used by Tesla and Panasonic in electric vehicles.

Lithium nickel oxide

Lithium nickel oxide (LiNiO₂), also called lithium nickelate, is a layered transition-metal oxide, first synthesized in 1954, that serves as the prototype of nickel-rich cathode materials in lithium-ion batteries.

Lithium niobate

Lithium niobate (LiNbO3, LN) is a synthetic ferroelectric crystal not found in nature, widely used in electro-optic modulators and in surface acoustic wave filters in smartphones.

Lithium nitrate

Lithium nitrate (LiNO₃) is an inorganic compound, the lithium salt of nitric acid, a deliquescent crystalline solid used as a strong oxidizing agent and molten-salt storage medium.

Lithium oxide

Lithium oxide (Li₂O), also called dilithium monoxide, is a white ionic solid known as a candidate tritium breeding ceramic for fusion reactor blankets, studied since the 1980s.

Lithium peroxide

Lithium peroxide ($ ext{Li}2 ext{O}2$) is an inorganic compound containing the peroxy anion. It is the solid discharge product of the lithium–oxygen battery, providing theoretical energy density.

Lithium tantalate

Lithium tantalate (LiTaO₃, often abbreviated LT) is a ferroelectric oxide single crystal grown by the Czochralski method and used at scale in smartphone radio-frequency filters, infrared detectors, and photonic circuits.

Lithium-6

Lithium-6 (⁶Li) is a stable fermionic isotope of lithium, about 7.59 percent of natural lithium, used in ultracold-atom experiments, including the 2002 Duke University observation of a strongly interacting Fermi gas.

Lithium-7

Lithium-7 is the heavier of lithium's two stable isotopes, a boson making up about 92.4 percent of natural lithium, central to Bose-Einstein condensation research and the cosmic lithium problem in cosmology.

Lithium-mediated ammonia synthesis

Lithium-mediated electrochemical nitrogen reduction to ammonia (Li-NRR) is an electrochemical route in which lithium metal reacts with nitrogen to form lithium nitride, which is protonated to release ammonia.

Lithology

Lithology is the description of rocks by observable physical characteristics such as color, mineral composition, grain size, texture, and degree of cementation; it defines lithostratigraphic units.

Lithosphere

The lithosphere is the Earth's rigid outer shell, comprising the crust and uppermost mantle; broken into tectonic plates, it is where essentially all earthquakes occur.

Lithosphere–asthenosphere boundary

The lithosphere–asthenosphere boundary (LAB) is the boundary in the uppermost mantle between the rigid lithosphere forming the tectonic plates and the ductile asthenosphere on which the plates move.

Litre

The liter (L) is a metric unit of volume equal exactly to one cubic decimeter; not an SI unit, it is accepted for use with the SI.

Little Christmas

Little Christmas, or Nollaig na mBan (Women's Christmas), is the Irish name for 6 January, the Epiphany and final day of Christmas, when men took over housework and women rested.