Differences between Lithium Hydroxide Monohydrate and Lithium Hydroxide

Lithium hydroxide monohydrate is the monohydrate form of lithium hydroxide and an important lithium salt, widely used as a lithium source for lithium battery cathode materials. Both are common chemical reagents and appear similar, both being white crystalline solids. However, their physical and chemical properties and uses differ slightly.

Physical and Chemical Property Differences

Structural Formula

Lithium hydroxide monohydrate has the molecular formula LiOH·H2O, containing one molecule of water of crystalline solid; whereas lithium hydroxide has the molecular formula LiOH, which does not contain any water of crystalline solid.

Solubility

Lithium hydroxide monohydrate is highly soluble in water, soluble in methanol, and slightly soluble in ethanol and isopropanol. Lithium hydroxide is also soluble in water, but its solubility is relatively low.

pH

Both are alkaline substances, so they have relatively high pH values. However, due to the presence of water of crystalline solid in lithium hydroxide monohydrate, its pH may be slightly higher than that of lithium hydroxide solution.

Differences in Applications

Lithium hydroxide monohydrate is primarily used in lithium battery manufacturing. The rapid growth of electric vehicles (EVs) and battery storage systems has significantly increased demand for lithium, particularly lithium hydroxide monohydrate (LiOH·H₂O). It is a key raw material in lithium-ion batteries, providing a lithium-ion conductor. It is also used in industrial applications such as coatings, glass, ceramics, and metal processing.

Lithium hydroxide is widely used in the preparation of lithium salts, lubricating greases, and biopharmaceuticals. It is also a catalyst for many organic synthesis reactions, such as the synthesis of esters and polymers. Lithium hydroxide is also used in industrial applications such as water treatment, metal surface treatment, and glass manufacturing.