Strategies to develop stable alkali metal anodes for rechargeable batteries

Alkali metal anodes are among the most promising candidates for next-generation high-capacity batteries like metal–air, metal–sulphur and all-solid-state metal batteries. The underlying interfacial mechanism of dendrite formation is not yet fully understood, preventing the practical implementation of metal batteries, particularly lithium, despite decades of research. Parallelly, there is an equal significance to the other alkali metal candidates viz sodium and potassium. The major challenges of alkali metal batteries, including dendrite formation, huge volume change, and unstable solid–electrolyte interface, are highlighted. Here, we also present an overview of the recent developments toward improving the anode interfaces. Given the enormous practical potential of alkali metal anodes as next-generation battery electrodes, we discuss some advanced probing techniques that enable a more complete understanding of the complex plating/stripping mechanism. Finally, perspectives and suggestions are provided on the remaining challenges and future directions in alkali metal battery research.