Advanced Na metal anodes

Na metal anode, benefiting from its high theoretical capacity and lowest electrochemical potential, is one of the most favorable candidates for future Na-based batteries with high energy density. Dendrite growth, volume change and high reactivity are the formidable challenges in terms of good cycling performance and high Coulombic efficiency as well as an expected safety guarantee of Na metal anode for the practical application. Solid electrolyte interphase (SEI) layer as an indispensable component of a battery, its formation and stability play the critical role in the feasibility of Na metal anode. In this review, we first discuss the current consideration and challenges of Na metal anode, and then summarize several strategies to suppress dendrite growth and improve electrochemical performance, including interface engineering, electrolyte composition, electrode construction, and so on. Finally, the conclusion and future perspective of potential development on Na metal anode are proposed.