Research Progress on Preparation of Lithium Metal by Vacuum Thermal Reduction

Molten salt electrolysis is a traditional method for lithium metal production, but it has some problems such as high cost of raw materials, the chlorine gas produced on anode and high sodium content in product. The vacuum thermal reduction method is to extract metal lithium by the difference of saturated vapor pressure after lithium is reduced. The product separation is simple, and the sodium content in the product is low. It has the advantages of low cost, simple process, high purity and no pollution gas in the production process. In this paper, the present situation and existing problems of many vacuum thermal reduction methods of lithium, such as carbon thermal reduction method, silicon thermal reduction method and aluminum-thermal reduction method are reviewed, and a novel aluminum-thermal reduction method is introduced, this process produces lithium from lithium hydroxide as raw material, with high whiteness aluminum hydroxide as a by-product, which is aimed to develop a new way for vacuum metal thermal reduction of lithium.