Toward Safe and Efficient Energy Storage: Progress and Challenges of Dendrite‐Free Sodium Metal Batteries

ABSTRACT Sodium metal batteries (SMB) and anode‐free sodium metal batteries (AFSMB) are considered as a key candidate for next‐generation energy storage technologies due to their advantages, such as high energy density and cost. However, their practical implementation remains fundamentally challenged by the complex interplay of thermodynamic instability and kinetic limitations at the Na anode interface. Moving beyond conventional, isolated approaches to dendrite suppression, this review presents a holistic design philosophy that integrates electrolyte engineering, interfacial control, and structural architecture. We critically dissect the electro‐chemo‐mechanical interplay governing sodium deposition, from the molecular level solvation structures in liquid and solid electrolytes to the nanoscale properties of the SEI and the three dimensional of current collectors. A dedicated analysis of external field regulation further reveals the profound impact of thermal and pressure management on plating homogeneity. By synthesizing these cross‐cutting strategies, we construct a coherent framework that links fundamental mechanisms to practical cell design. Finally, we pinpoint persistent scientific gaps and outline emerging paradigms, including advanced in‐situ diagnostics and AI‐guided materials discovery, to illuminate the path toward intrinsically safe and commercially viable sodium metal batteries.