LithiumbromidWasserSystem

Lithium bromide is a chemical compound with the formula LiBr. It is a white, odorless crystalline salt that is highly hygroscopic and readily forms hydrates, such as LiBr·6H2O. In its anhydrous form it is soluble in water and many organic solvents, and it has a relatively high lattice energy compared with some other alkali metal bromides. It is stable at ambient temperatures but should be protected from moisture and heat in storage due to its deliquescent nature.

LiBr is typically prepared by treating hydrobromic acid with lithium carbonate: 2 Li2CO3 + 4 HBr -> 4 LiBr + 2 CO2 + 2 H2O, or by the direct reaction of lithium metal with bromine, 2 Li + Br2 -> 2 LiBr. The salt is commercially available in anhydrous form or as hydrates.

The largest uses are as a drying agent for gas streams and as the absorbent in LiBr–water absorption chillers for air conditioning and heat pumps. It is also used in certain chemical synthesis as a bromide source and in some specialty pharmaceutical preparations.

LiBr dust or solutions can irritate skin and eyes; ingestion may be harmful. Its hygroscopicity means containers must be tightly sealed and stored away from moisture. Proper handling includes the use of gloves and eye protection to minimize irritation and exposure.