Lithium sulfate

Li HSO4 919XA137JK Lithium sulfate is a white inorganic salt with the formula Li2SO4. It is the lithium salt of sulfuric acid. Lithium sulfate is a white inorganic salt with the formula Li2SO4. It is the lithium salt of sulfuric acid. Lithium sulfate 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 endothermic process. This property is shared with few inorganic compounds, such as the lanthanoid sulfates. Lithium sulfate crystals, being piezoelectric, are also used in ultrasound-type non-destructive testing because they are very efficient sound receivers. However, they do suffer in this application because of their water solubility. 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 has pyroelectric properties. When aqueous lithium sulfate is heated, the electrical conductivity also increases. The molarity of lithium sulfate also plays a role in the electrical conductivity; optimal conductivity is achieved at 2M and then decreases. When solid lithium sulfate is dissolved in water it has an endothermic disassociation. This is different than sodium sulfate which has an exothermic disassociation. The exact energy of disassociation is difficult to quantify as it seems relative to the mols of the salt added. Small amounts of dissolved lithium sulfate have a much greater temperature change than large amounts. Lithium sulfate has two different crystal phases. In common phase II form, Lithium sulfate has a sphenoidal monoclinic crystal system that has edge lengths of a = 8.23Å b = 4.95Å c = 8.47Å β = 107.98°. When lithium sulfate is heated passed 130 ℃ it changes to a water free state but retains its crystal structure. It is not until 575 ℃ when there is a transformation from phase II to phase I. The crystal structure changes to a face centered cubic crystal system, with an edge length of 7.07Å. During this phase change, the density of lithium sulfate changes from 2.22 to 2.07 g/cm3. Lithium sulfate is used to treat bipolar disorder (see lithium pharmacology). 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.