Lithium iodide, or LiI, is a compound of lithium and iodine. When exposed to air, it becomes yellow in color, due to the oxidation of iodide to iodine. It crystallizes in the NaCl motif. It can participate in various hydrates.
3D model (JSmol)
CompTox Dashboard (EPA)
|Molar mass||133.85 g/mol|
|Appearance||White crystalline solid|
|Density||4.076 g/cm3 (anhydrous)|
3.494 g/cm3 (trihydrate)
|Melting point||469 °C (876 °F; 742 K)|
|Boiling point||1,171 °C (2,140 °F; 1,444 K)|
|1510 g/L (0 °C)|
1670 g/L (25 °C)
4330 g/L (100 °C) 
|Solubility||soluble in ethanol, propanol, ethanediol, ammonia|
|Solubility in methanol||3430 g/L (20 °C)|
|Solubility in acetone||426 g/L (18 °C)|
Refractive index (nD)
Heat capacity (C)
|0.381 J/g K or 54.4 J/mol K|
|75.7 J/mol K|
Std enthalpy of
|-2.02 kJ/g or −270.48 kJ/mol|
Gibbs free energy (ΔfG˚)
|NFPA 704 (fire diamond)|
|Safety data sheet (SDS)||External MSDS|
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
(what is ?)
Lithium iodide is used as a solid-state electrolyte for high-temperature batteries. It is also the standard electrolyte in artificial pacemakers due to the long cycle life it enables. The solid is used as a phosphor for neutron detection. It is also used, in a complex with Iodine, in the electrolyte of dye-sensitized solar cells.
Lithium iodide was used as a radiocontrast agent for CT scans. Its use was discontinued due to renal toxicity. Inorganic iodine solutions suffered from hyperosmolarity and high viscosities. Current iodinated contrast agents are organoiodine compounds.
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