Sodiophilic Na ₃ Sb Framework‐Regulated Sodium Deposition and Interphase Evolution for Dendrite‐Free and Long‐Life Sodium Metal Batteries

ABSTRACT

Sodium (Na) metal anodes are attracting great attention as next‐generation energy storage systems due to their high theoretical capacity, abundant resources, and low cost. However, an unstable solid‐electrolyte interphase (SEI), uncontrolled dendrite growth, and large volume changes are major factors limiting the practical application of Na metal anodes. Herein, we develop a Na‐Sb alloy anode featuring a three‐dimensional sodiophilic Na ₃ Sb framework embedded within a metallic Na matrix. The interconnected Na ₃ Sb framework homogenizes the Na ⁺ flux and provides abundant Na nucleation sites, enabling uniform Na deposition while effectively suppressing dendrite growth. Moreover, the engineered interface promotes the formation of a dense, NaF‐rich inorganic SEI with high mechanical strength and chemical stability, which effectively accommodates volume changes and stabilizes the Na metal/electrolyte interface during repeated cycling. Consequently, the NSF‐3||NSF‐3 symmetric cell delivers remarkably stable cycling for over 1000 h at 0.5 mA cm ⁻² with a capacity of 0.5 mAh cm ⁻² , exhibiting significantly improved interfacial stability and Na plating behavior. This work demonstrates that constructing a sodiophilic Na ₃ Sb framework is an effective strategy for regulating Na deposition and stabilizing the Na metal interface, providing a practical pathway toward high‐energy‐density and long‐life sodium metal batteries.