Lithium iodide is widely used in high-temperature batteries, particularly in solid-state and thermal batteries for aerospace and military applications, due to its high ionic conductivity and thermal stability. It also serves as an electrolyte in lithium-iodine batteries for implantable medical devices like pacemakers, providing long shelf life, high reliability, and safety under physiological conditions. It is used in humidity sensors owing to its hygroscopic nature and ability to conduct electricity when hydrated. In organic synthesis, lithium iodide functions as a catalyst or reagent, particularly in iodination reactions and carbon-carbon bond formation. In nuclear medicine, it is employed in radiation detection systems, including gamma sensors, benefiting from its capacity to form scintillation crystals when doped with other elements. Additionally, it finds applications in research on photovoltaics and solid-state conductive materials.