The Li-Se battery and its C/Se composite electrode: Opportunities and challenges

Selenium is a novel and promising cathode material in lithium ion batteries owing to its high electronic conductivity and a theoretical volumetric capacity comparable to that of S.As a congener of sulfur (S), Se has a similar lithiation mechanism to S in charge/discharge when used as the cathode material of a Li-Se battery. However, similar to the Li-S battery, the Li-Se battery suffers from a shuttle effect that leads to poor cycle performance and low Coulombic efficiency. This review summarizes recent developments, highlights the excellent performance of Li-Se batteries and focuses on improvements to the carbon/Se composite electrode. The main obstacles are also discussed. The use of porous carbons, especially graphene-based materials, for improving the performance of the Se electrode in high performance Li-Se batteries is highlighted and discussed.