Guiding Uniform Sodium Deposition through Host Modification for Sodium Metal Batteries

Abstract Room‐temperature Na metal batteries represent an emerging energy storage technology beyond Li‐ion batteries, owing to the high specific capacity and high natural abundance of Na. However, Na metal anodes are plagued with multiple challenges including unstable solid electrolyte interphase, undesirable dendrite growth, and large volumetric expansion, leading to low Coulombic efficiency during Na plating and stripping. To this end, mechanically stable and sodiophilic hosts with nano‐ or micro‐structured materials have been investigated to accommodate Na in the structured spacing or gaps for enhanced cyclability. In this concept, we will discuss the key concepts and latest developments in guiding uniform Na deposition through host modification, especially carbon, inorganic and polymeric materials. Future prospects and outlook will also be provided, including artificial interphase design, solid‐state electrolytes, and precise nanoscale characterization to improve our fundamental understanding of Na deposition and spur this burgeoning field in Na metal batteries.