碳酸锂，Lithium carbonate；battery grade, ≥99.9% trace metals basis

Lithium carbonate is a white, crystalline salt that only exists in the anhydrous form. The salt is soluble in water, but poorly, and it is insoluble in alcohols and acetone. The solubility of lithium carbonate in water decreases with increasing temperature, which is unusual for a salt. Its solubility increases with partial pressure of carbon dioxide, which drives the equilibrium towards the more soluble metastable bicarbonate. These properties of its solubility are often exploited in its purification.
Lithium carbonate is an important industrial chemical, primarily as a precursor to lithium fluoride and lithium hydroxide, key precursors for compounds used in lithium-ion batteries. It is also used directly in ceramic glazes, glasses, and fireworks, among other industrial applications.
Lithium carbonate is produced in several ways, usually involving extracting lithium from the earth. One common extraction method involves mining and acid leaching from spodumene ores (lithium aluminum silicate). The ore is concentrated, baked at high temperature to change the crystal structure to a digestible phase, then digested with sulfuric acid to form a concentrate. Reacting the lithium sulfate concentrate with sodium carbonate forms the raw lithium carbonate that is further purified and dried. Another method involves processing and purifying underwater brine, which is pumped to the surface and dried by passive evaporation. The resulting salts are converted to lithium carbonate and subsequently purified.

 

Lithium carbonate is used in the preparation of many lithium compounds, most notably lithium iron phosphate (LiFePO₄).[1] A common synthetic strategy for synthesizing lithium metal oxides involves thermally decomposing lithium carbonate, which serves effectively as a convenient, in-situ source of lithium oxide by cleanly evolving carbon dioxide. Typically, lithium carbonate is mixed or ball-milled with other metal carbonates, metal oxides, and phosphates. Then the mixture is heated at a low temperature (e.g. 350 °C) and subsequently at a higher temperature (e.g. 600 °C) to complete the reaction and improve the crystallinity of the product. Researchers have used this technique to prepare exciting new materials for lithium-ion batteries, like Li₂Ru₁-ySnyO₃ as a cathode material[2] and Li₇La₃Zr₂O₁₂ (LLZ) as a solid-state electrolyte.[3]