3D Sb‐Based Composite Framework with Gradient Sodiophilicity for Ultrastable Sodium Metal Anodes

Abstract Sodium (Na) dendrites, as the ringleader for triggering safety concerns, have restricted the practical application of sodium metal batteries (SMBs). The fundamental reason is due to the high activity of Na metal anodes, which can continuously induce the interfacial side reactions and Na dendrites growth, resulting in rapid capacity deterioration, low Coulombic efficiency, and even internal short‐circuit. In order to enhance the safety and stability of SMBs, a flexible 3D hollow porous carbon nanofiber framework embedded with Sb nanoparticles (Sb@HPCNF) is reported by integrating interface chemistry and structural engineering. The 3D Sb@HPCNF framework with gradient sodiophilicity can maintain highly reversible Na plating–stripping cycles at 5 mA cm −2 for >550 h and possesses a low overpotential of 24 mV. In addition, the full‐cells using Na 3 V 2 (PO 4 ) 3 cathode and Sb@HPCNF‐Na anode exhibit impressive long‐term cycling stability and excellent high‐rate performance. This study provides a new insight on constructing functionalized 3D composite framework with gradient sodiophilicity toward next‐generation high‐safety and high‐energy SMBs.