Lithium (Li): Properties & Uses

Lithium element

Although lithium element was discovered in mineral petalite (LiAlSi4O10) in 1817, it was first isolated in 1855 by the electrolysis of lithium oxide (LiO2). Its name was derived from the Greek word “lithos”, which means rock. Lithium belongs to the alkali group (group 1) with symbol ‘Li’ and atomic number 3 in the periodic table.


Lithium metal can be cut with a knife easily as it is soft enough, and when it is cut, it appears with silvery-white lustre. This appearance usually does not last long as it quickly changes to grey because oxygen present in the air oxidizes the lithium to lithium oxide.

Silvery white lustre of lithium

The silvery-white lustre of lithium

Physical Properties


Lithium does not exist freely in nature. It is found in combined forms near all the igneous rocks and sometimes found in mineral water springs. Naturally occurring minerals, which contain lithium, are spodumene (LiAl(SiO3)2), petalite, lepidolite, and amblygonite.

Spodumene processing for lithium extraction

Spodumene Processing for Lithium Extraction

Flame Colour

Lithium salts impart a characteristic crimson red colour to an oxidizing flame. This characteristic flame colour helps in the detection of lithium salts, and its concentration in the sample is determined by the flame photometry or atomic absorption spectroscopy (academic purpose).

Melting and Boiling Point

Lithium has a melting point of 180°C, and it is the highest melting point in comparison to other alkali metals. Its boiling point is 1342°C.


Lithium has a density of about 0.534 gram per centimetre cube. It is one of the metals that can float on water because its density is less than that of water whose density is 1.0 gram per centimetre cube. It can also float on the lightest hydrocarbon oils.

Atomic Properties

It has a single electron in its valence shell that is easily given up to form a cation. It makes lithium a good conductor of heat and electricity as well as a highly reactive element. However, molten lithium is significantly more reactive than its solid form.


Chemical Properties

Reactivity towards Water

Being an alkali metal, lithium reacts with water to form lithium hydroxide and dihydrogen. Its reaction with water is less vigorous as compared to other alkali metals, such as sodium and potassium, which react explosively with water. Its small size and high hydration energy is attributed to this anomalous behaviour.

2Li(s) + 2H2O(l) → 2LiOH(aq) + H2(g)

Lithium in water

Reactivity towards Air

Lithium reacts vigorously with oxygen, which results in the formation of its monoxide.

4Li + O2 → 2Li2O (Lithium oxide)

It also reacts with the nitrogen to form lithium nitride (Li3N). Due to its reactivity with air and water, it is usually kept in paraffin wax.

Reactivity towards Halogens

Although alkali metals react with halogens to form ionic halides, lithium halides show somewhat covalent character. This is exceptional because of high polarisation capability of lithium-ion, and its small size that shifts its character to somewhat covalent. Among lithium halides, lithium iodide is the most covalent in nature.

Lithium iodide

 Reducing Nature

Alkali metals are the strong reducing agents. Lithium is the strongest reducing agent due to its small size of ion, which accounts for the highest hydration enthalpy of lithium. Thus, lithium has a great tendency to lose electrons in the solution. Hence, lithium is the strongest reducing agent.

Lithium as strongest reducing agent.

Organic chemistry

Organolithium reagents are those reagents, in which there is a direct bond between carbon and lithium. These are highly reactive reagents and are used as bases. Organolithium reagents are commercially available in solution form for various laboratory organic synthesis. They have also been applied in synthesis in the pharmaceutical industry.

Example of organolithium reagent

Organolithium reagent

 Diagonal relationship with Magnesium

Lithium has a diagonal relationship with magnesium. Both elements have many similarities, such as they possess the same atomic and ionic radius, and both have almost similar electronegativities. Both elements form nitrides when they react with nitrogen, and they form oxides and peroxides when they react with oxygen.Diagonal relationship in Main group elements


The two stable isotopes of lithium that occur in nature are { 6 }_{ Li } and { 7 }_{ Li }. Although seven radioisotopes of lithium have been characterized, the most stable radioisotopes are { 8 }_{ Li } with a half-life of 838ms, and { 9 }_{ Li } with a half-life of 178ms. During natural processes, such as mineral formation, lithium isotopes are fractionated.

Stable isotopes of Lithium

Stable Isotopes of Lithium


1. Electronics Industry

Lithium-ion batteries

Lithium batteries are being used since the early 1900s in the electronics industry. These type of batteries are non-rechargeable batteries. In the early 1980s, research on lithium-ion batteries were started, and these batteries were first commercialized in 1991. Lithium-ion batteries are rechargeable batteries, which can be recharged many times before their degradation. Lithium batteries are used where extendable battery life is vital, such as watches, hearing aids, digital cameras, calculators; whereas lithium-ion batteries are used where frequent recharging is needed, such as mobile phones, laptops, tablets, and emergency power backups. Li-ion batteries are also used to supply energy to medical equipment, electric vehicles, and power tools. These are widely used in portable power stations because they provide several advantages, such as high energy density, low maintenance, and high cell voltage.

Lithium batteries

2. Ceramics

When lithium carbonate is added in the manufacturing of ceramics bodies, it offers many advantages, such as it lowers the firing temperature and thermal expansion, which increases the strength of ceramic bodies, and improves its colour, strength and lustre.

Lithium Ceramics

3. Glasses

In certain types of glasses such as container glass, flat glass, pharmaceutical glass, speciality glass (used in touch screens), and fibreglass, lithium is being used. When lithium is added, it increases the glass melt rate, and hence, lowers the viscosity and melt temperature.Glasses

4. Lubricating Greases

The most common use of lithium is in the manufacturing of greases. Lithium hydroxide is a strong base, and when it is heated with a fat, it produces a soap, which is made up of lithium stearate. Lithium soap has the ability to thicken oils, and it is used to manufacture all-purpose, high-temperature lubricating greases.

Lithium grease

Lithium Grease

5. Medicine

Lithium salts are widely used in medicines for the treatment of “bipolar disorder” (a mental disorder that is caused by periods of depression, and abnormally elevated mood that lasts from days to weeks).

Lithium drug

6. Air Purification

In confined areas, such as abroad spacecraft and submarines, lithium hydroxide and lithium peroxide are the salts of lithium, which are used for carbon dioxide removal, and hence for air purification. Lithium hydroxide absorbs carbon dioxide from the air by forming lithium carbonate, and it is preferred over other alkaline hydroxides due to its low weight.

2LiOH(s) + CO2(g)→ Li2CO3(s) + H2O(g)

Lithium peroxide (Li2O2) in presence of moisture, reacts with carbon dioxide to form lithium carbonate and oxygen.

2 Li2O2 + 2 CO2 → 2 Li2CO3 + O2

Lithium as airpurifier in Submarines

Lithium as an Air purifier in Submarines

7. Military Applications

Metallic lithium and its hydrides, such as Li[AlH4], are used as high-energy additives to rocket propellants. Lithium hydride containing lithium-6 is used in thermonuclear weapons, where it serves as fuel for the fusion stage of the bomb.

Rocket Propellents

Rocket Propellents

8. Lithium Alloys

Lithium-aluminium alloys are widely used in the aerospace industry. Al-Li alloys are lighter and have high tensile, and yield strength as compared to the conventional high-strength aluminium alloys. They are resistant to fatigue crack propagation. It is also used to make other useful alloys, such as with lead to make ‘white metal’ bearings for metal engines, and with magnesium to make armour plates.

Lithium alloys

Lithium Alloys

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