Applications of Lithium Sulfate
| Jerry Huang
Lithium sulfate is a white inorganic salt with the formula Li2SO4. It is the lithium salt of sulfuric acid. It is soluble in water, though it does not follow the usual trend of solubility versus temperature — its solubility in water decreases with increasing temperature, as its dissolution is an exothermic process. Since it has hygroscopic properties, the most common form of lithium sulfate is lithium sulfate monohydrate. Anhydrous lithium sulfate has a density of 2.22 g/cm3, but weighing lithium sulfate anhydrous can become cumbersome as it must be done in a water lacking atmosphere.
Lithium sulfate is researched as a potential component of ion conducting glasses. Transparent conducting film is a highly investigated topic as they are used in applications such as solar panels and the potential for a new class of battery. In these applications, it is important to have a high lithium content; the more commonly known binary lithium borate (Li₂O · B₂O₃) is difficult to obtain with high lithium concentrations and difficult to keep as it is hygroscopic. With the addition of lithium sulfate into the system, an easily produced, stable, high lithium concentration glass is able to be formed. Most of the current transparent ionic conducting films are made of organic plastics, and it would be ideal if an inexpensive stable inorganic glass could be developed.
Lithium sulfate has been tested as an additive for Portland cement to accelerate curing with positive results. Lithium sulfate serves to speed up the hydration reaction which decreases the curing time. A concern with decreased curing time is the strength of the final product, but when tested, lithium sulfate doped Portland cement had no observable decrease in strength.
Lithium sulfate is used to treat bipolar disorder. Lithium (Li) is used in psychiatry for the treatment of mania, endogenous depression, and psychosis; and also for treatment of schizophrenia. Usually lithium carbonate (Li₂CO₃) is applied, but sometimes lithium citrate (Li₃C6H5O7), lithium sulfate or lithium oxybutyrate are used as alternatives.
Lithium sulfate has been used in organic chemistry synthesis. Lithium sulfate is being used as a catalyst for the elimination reaction in changing n-butyl bromide to 1-butene at close to 100% yields at a range of 320℃ to 370℃. The yields of this reaction change dramatically if heated beyond this range as higher yields of 2-butene is formed.