Lithium fluoride is an alkali metal salt with the chemical formula LiF that occurs naturally as a mineral griceite. Let us study some facts about this metal halide in detail.
The uses of lithium fluoride are listed below,
- In the production of batteries
- Optical instrument
- Formation of molten salts
- In nuclear reactors
- As a detector
- Used as light-emitting diodes
In this article, we will discuss the uses of lithium fluoride in detail.
In the production of batteries
Lithium fluoride reacts with PCl5 (phosphorus pentachloride) and HF (hydrogen fluoride) to produce the precursor (lithium hexafluorophosphate) that is required to make electrolytes of lithium-ion batteries.
- LiF forms distinct optics for the vacuum ultraviolet spectrum as it has a large band gap so its crystals are transparent to UV light.
- LiF is widely used as a flux in the production of ceramics, such as glasses, enamels, and glazes.
- LiF also serves as an analysis crystal in X-ray spectroscopy and in UV-transmission windows.
Formation of molten salts
Lithium fluoride has high applications in molten salt chemistry as,
- LiF facilitates the electrolysis of molten K[HF2] (potassium bifluoride) to produce fluoride ions as it forms the Li-C-F interface on the carbon electrodes.
- A mixture of LiF along with NaF (sodium fluoride), and KF (potassium fluoride) produces a highly useful molten salt named FLiNaK.
In nuclear reactors
Lithium fluoride gives the basic fluoride salt mixtures that are used in LiF nuclear reactors as LiF is exceptionally stable; it is mixed with BeF2 (beryllium fluoride) to give a base solvent, FLiBe that has the best neutronic properties to be used in the reactors.
As a detector
- LiF is used in detecting the ionizing radiations coming from beta-particles, gamma rays, and neutron emissions.
- LiF nanopowder functions as a neutron-reactive backfill material for semiconductor neutron detectors.
In light-emitting diodes (LEDs)
LiF acts as a coupling layer to enhance electron injection in organic LEDs with the thickness of the layer around 1 nm.
Lithium fluoride occurs as transparent crystals which are hygroscopic in nature. LiF is highly dense (density= 2.635 g/cm3) and has very low solubility in water. The primary use of LiF is the formation of molten salts.