The rise of lithium–selenium batteries

The lithium–selenium (Li–Se) battery is an alternative to its sulfur counterpart with some noticeable advantages, such as the significantly higher electrical conductivity of Se and better electrochemical performance. Although the idea of a Li–Se battery dates to the 1960s, over the past four years it has been revisited as a practical potential candidate for electrochemical energy storage. Despite similar problems of Li–Se and lithium–sulfur (Li–S) batteries, such as the so-called shuttle effect, the research strategies go in different directions because of new opportunities offered by the Li–Se batteries. For instance, Li–Se batteries can perform better in the conventional carbonate-based electrolytes, in which polysulfides are chemically unstable. The present manuscript comprehensively reviews the current status of the Li–Se battery based on the achievements during its short history. Furthermore, a promising possibility is the lithium–(sulfur/selenium) battery, utilizing a sulfur/selenium cathode that can gain the advantages of both batteries. Other batteries in this family such as sodium–selenium and magnesium–selenium are also considered.