Lithium, mainly used in electrical energy storage, has also been studied in thermal energy storage. It is recognized as a “critical material” and is produced from minerals and from brines. Chile is one of the biggest producers, here from brine and with lower costs than in other countries. With sensible heat storage, in solar power plants lithium is seen as a way to improve the properties of molten salts used today. The low melting point in these ternary salts with lithium, represent a considerable reduction in the maintenance and operational costs associated with current solar technology, demonstrating that the fluids showed, are potential candidates for thermal energy storage (TES) in concentrated solar plants (CSP) plants. Many materials have been studied and proposed to be used as phase change materials (PCM). Between the multiple materials studied to be used in PCM, lithium materials and mixtures are listed as potential PCM for building applications and for high temperature applications. In thermochemical energy storage, lithium compounds have been used mainly in chemical heat pumps, following their use in absorption cooling.