Both lithium carbonate and lithium hydroxide are raw materials for batteries, but lithium carbonate has consistently been cheaper than lithium hydroxide in the market. What are the differences between these two materials?
First, from the perspective of preparation process, both can be extracted from spodumene, and the cost difference is not significant. However, if the two are converted into each other, additional costs and equipment are required, which is not cost-effective.
The main method for preparing lithium carbonate is the sulfuric acid process. Lithium sulfate is obtained by reacting sulfuric acid with spodumene. Sodium carbonate is then added to the lithium sulfate solution, followed by precipitation and drying to prepare lithium carbonate.
The main method for preparing lithium hydroxide is the alkaline method, which involves roasting spodumene with calcium hydroxide. Another method is the so-called sodium carbonate pressurization method, which involves first preparing a lithium-containing solution and then adding lime to the solution to prepare lithium hydroxide.
In summary, spodumene can be used to produce both lithium carbonate and lithium hydroxide, but the process routes differ, the equipment cannot be shared, and the cost is not significantly different. However, the cost of producing lithium hydroxide from salt lake brine is much higher than that of producing lithium carbonate.
Secondly, in terms of applications, high-nickel ternary lithium batteries must use lithium hydroxide. NCA and NCM811 must use battery-grade lithium hydroxide, while NCM622 and NCM523 can use either lithium hydroxide or lithium carbonate. The hydrothermal preparation of lithium iron phosphate (LFP) products also requires lithium hydroxide. Generally speaking, products produced using lithium hydroxide typically exhibit superior performance.
