Lithium hydroxide is an

inorganic compound In chemistry, an inorganic compound is typically a chemical compound that lacks carbon–hydrogen bonds, that is, a compound that is not an organic compound. The study of inorganic compounds is a subfield of chemistry known as '' inorganic chemi ...

with the formula LiOH. It can exist as anhydrous or hydrated, and both forms are white hygroscopic solids. They are soluble in water and slightly soluble in

ethanol Ethanol (abbr. EtOH; also called ethyl alcohol, grain alcohol, drinking alcohol, or simply alcohol) is an organic compound. It is an alcohol with the chemical formula . Its formula can be also written as or (an ethyl group linked to a h ...

. Both are available commercially. While classified as a strong base, lithium hydroxide is the weakest known alkali metal hydroxide.

Production

The preferred feedstock is hard-rock spodumene, where the lithium content is expressed as % lithium oxide.

Lithium carbonate route

Lithium hydroxide is often produced industrially from lithium carbonate in a metathesis reaction with

calcium hydroxide Calcium hydroxide (traditionally called slaked lime) is an inorganic compound with the chemical formula Ca( OH)2. It is a colorless crystal or white powder and is produced when quicklime ( calcium oxide) is mixed or slaked with water. It has m ...

: : The initially produced hydrate is dehydrated by heating under vacuum up to 180 °C.

Lithium sulfate route

An alternative route involves the intermediacy of lithium sulfate: :α- spodumene → β-spodumene :β-spodumene + CaO → + ... : : The main by-products are

gypsum Gypsum is a soft sulfate mineral composed of calcium sulfate dihydrate, with the chemical formula . It is widely mined and is used as a fertilizer and as the main constituent in many forms of plaster, blackboard or sidewalk chalk, and dr ...

and sodium sulphate, which have some market value.

Commercial setting

According to Bloomberg, Ganfeng Lithium Co. Ltd. (GFL or Ganfeng) and Albemarle were the largest producers in 2020 with around 25kt/y, followed by Livent Corporation (FMC) and SQM. Significant new capacity is planned, to keep pace with demand driven by vehicle electrification. Ganfeng are to expand lithium chemical capacity to 85,000 tons, adding the capacity leased from Jiangte, Ganfeng will become the largest lithium hydroxide producer globally in 2021. Albemarle's Kemerton WA plant, originally planned to deliver 100kt/y has been scaled back to 50kt/y. In 2020 Tianqi Lithium's, plant in Kwinana, Western Australia is the largest producer, with a capacity of 48kt/y.

Applications

Lithium ion batteries

Lithium hydroxide is mainly consumed in the production of

cathode A cathode is the electrode from which a conventional current leaves a polarized electrical device. This definition can be recalled by using the mnemonic ''CCD'' for ''Cathode Current Departs''. A conventional current describes the direction i ...

materials for lithium ion batteries such as lithium cobalt oxide () and lithium iron phosphate. It is preferred over lithium carbonate as a precursor for lithium nickel manganese cobalt oxides.

Grease

A popular lithium grease thickener is lithium 12-hydroxystearate, which produces a general-purpose lubricating grease due to its high resistance to water and usefulness at a range of temperatures.

Carbon dioxide scrubbing

Lithium hydroxide is used in breathing gas purification systems for

spacecraft A spacecraft is a vehicle or machine designed to spaceflight, fly in outer space. A type of artificial satellite, spacecraft are used for a variety of purposes, including Telecommunications, communications, Earth observation satellite, Earth ...

, submarines, and

rebreather A rebreather is a breathing apparatus that absorbs the carbon dioxide of a user's exhaled breath to permit the rebreathing (recycling) of the substantially unused oxygen content, and unused inert content when present, of each breath. Oxygen is ...

s to remove

carbon dioxide Carbon dioxide ( chemical formula ) is a chemical compound made up of molecules that each have one carbon atom covalently double bonded to two oxygen atoms. It is found in the gas state at room temperature. In the air, carbon dioxide is t ...

from exhaled gas by producing lithium carbonate and water: : or : The latter, anhydrous hydroxide, is preferred for its lower mass and lesser water production for respirator systems in spacecraft. One gram of anhydrous lithium hydroxide can remove 450 cm³ of carbon dioxide gas. The monohydrate loses its water at 100–110 °C.

Precursor

Lithium hydroxide, together with lithium carbonate, is a key intermediates used for the production of other lithium compounds, illustrated by its use in the production of lithium fluoride: :

Other uses

It is also used in

ceramic A ceramic is any of the various hard, brittle, heat-resistant and corrosion-resistant materials made by shaping and then firing an inorganic, nonmetallic material, such as clay, at a high temperature. Common examples are earthenware, porcelai ...

s and some Portland cement formulations, where it is also used to suppress ASR ( concrete cancer). Lithium hydroxide ( isotopically enriched in lithium-7) is used to alkalize the reactor coolant in

pressurized water reactor A pressurized water reactor (PWR) is a type of light-water nuclear reactor. PWRs constitute the large majority of the world's nuclear power plants (with notable exceptions being the UK, Japan and Canada). In a PWR, the primary coolant (water) is ...

s for corrosion control. It is good radiation protection against free neutrons.

Price

In 2012, the price of lithium hydroxide was about $5-6/kg. In December 2020 it had risen to $9/kg On 18 March 2021 the price had risen to US$11.50/kg

References

External links

* (anhydrous) * (monohydrate) {{Authority control Lithium compounds Hydroxides *