Long Cycle Life and High‐Rate Sodium Metal Batteries Enabled by Regulating 3D Frameworks with Artificial Solid‐State Interphases

Abstract The major challenge for sodium metal anodes is Na dendrite growth owing to the unstable and fragile solid–electrolyte interphase (SEI), leading to terrible cycle life and safety hazards. Constructing a robust SEI around a 3D porous host is considered to be a facile and efficient approach to stabilize Na metal anodes. Here, a durable 3D porous SnCl 4 @Na–rGO metal anode is fabricated by the in situ chemical reaction of SnCl 4 ‐containing carbonate electrolyte with Na–rGO. Attributed to the robust SEI and the stereoscopic structure, the symmetric cells achieve a prolonged cycle life of 500 h without voltage fluctuation at 2 mA cm −2 and 2 mAh cm −2 . Moreover, the Na 3 V 2 (PO 4 ) 3 ||SnCl 4 @Na–rGO full cell exhibits long‐term cycle stability ( > 600 cycles) and remarkable capacity retention ( > 92%). The novel approach provides an efficacious strategy for the practical implementation of Na metal batteries.