Recent development of Na metal anodes: Interphase engineering chemistries determine the electrochemical performance

Sodium (Na) metal is not only the frequently used counter electrode in half-cell evaluation for Na storage materials, but also the essential anode for emerging room-temperature Na metal batteries (SMBs) in various types such as Na-sulfur, Na-oxygen, and Na-carbon dioxides batteries. Recent research into the Na metal employed in batteries has placed a spotlight on enhancing electrochemical stability of Na metal anode by addressing the problems of undesired dendrite growth and instable solid electrolyte interphase (SEI). Especially, the latter is recognized to be more responsible for performance failure in Na metal anode. Here, this review is focused to summarize the recent advancement of the interphase engineering chemistries of Na metal anode. The main origins of performance failure regarding interphase chemistries are comparatively described in detail, emphasizing that health SEI formed on Na-metal surface has a decisive role in anodic electrochemical behaviors. Subsequently, the representative strategies involved with constructing stable interphase are highlighted including electrolyte modulations, artificial coating and conductive matrix. Finally, future prospects into interphase chemistries of Na metal anode are proposed in the last section. This review will provide a clear figure of the state-of-art status research and the development trend of Na metal anode.