Review on the production of high-purity lithium metal

Abstract

While to date the element lithium (Li) has received eminent fame for the application of its compounds in lithium ion batteries (LIBs), its pure form of metallic Li is expected to achieve more fame in the future for its critical role in some new applications, for instance, Li-metal batteries. Such applications will require massive production of high-purity metallic Li, about a million tons at full scale development. However, the current industry for Li production faces two challenges: low production at the level of only two thousand tons per year and high cost due to tough manufacturing conditions. Very recently, several prestigious research groups published creative papers about Li production, which in the future would attract intensive efforts in this field. In order to provide the community with insightful views on the future production of Li, this review summarizes all the major methods of directly producing high-purity Li in the literature. After describing the production principles and key features, the article is concluded with our perspectives on future directions of producing metallic Li.