Recent Progress and Insights in the Design of Stable Sodium Metal Anodes

Abstract High‐energy sodium (Na)‐metal batteries have attracted considerable attention due to their high theoretical capacity and abundant Na resources. However, the development of room‐temperature Na metal anodes faces several significant challenges. First, the fragile solid electrolyte interphase (SEI) and highly reactive nature of Na metal cause continuous consumption of electrolytes. Furthermore, Na dendrite growth is more vigorous than the Li counterpart due to the unstable SEI, leading to rapid decay in Coulombic efficiency and short‐circuit issues. Additionally, volume expansion and the generation of flammable gases during Na plating and stripping are significant issues in practical Na metal batteries. This review provides a comprehensive summary of proposed solutions aimed at addressing these problems, including electrolyte modification design, protective layer implementation, and structured Na‐metal anode development with the goal of achieving a stable interface, reversible Na plating/stripping processes, and a prolonged cycling lifespan. Furthermore, this review discusses the underlying principles behind these strategies while offering insights into future research directions.