Lithium metal rechargeable batteries were extensively examined from the 1960s until the discovery and development of the lithium ion battery in 1991¹. The earlier work was compromised by the lack of development of materials of adequate purity, particularly with regard to water content in positive electrode materials and electrolyte solutions. As this aspect was solved by the increasing availability of battery grade materials, some of the basic limitations of the battery became more evident and work was advanced to cope with these problems. Complete solutions were not found when the advent of lithium ion batteries succeeded in avoiding the most severe problems of lithium metal negative electrodes. The state of the art in 1991 will be briefly summarized and the likely directions of continued progress in lithium metal rechargeable batteries will be discussed. Also, the potential advantages and disadvantages of lithium metal batteries will be given. Finally, the state of present art of lithium metal batteries for both solid and liquid electrolytes will be presented and the likelihood of success of present approaches will be considered.

¹For the history of lithium ion batteries see: G. E. Blomgren, The Development and Future of Lithium Ion Batteries, doi: 10.1149/2.0251701jesJ. Electrochem. Soc. 2017, 164,A5019-A5025