1D Sb2S3@nitrogen-doped carbon coaxial nanotubes uniformly encapsulated within 3D porous graphene aerogel for fast and stable sodium storage

The Sb 2 S 3 anode materials with high theoretical capacity were troubled by their sluggish electrochemical kinetics and huge volume expansion in sodium-ion batteries. Herein, we firstly designed a unique Sb 2 S 3 @nitrogen-doped carbon (Sb 2 S 3 @N-C) nanotube encapsulated by porous graphene aerogel to solve the above technical barrier. The composite aerogel with ingenious structure was creatively designed by coating polydopamine (PDA) onto the Sb 2 S 3 nanorods. The PDA was not only a precursor of nitrogen-doped carbon (N-C) layer adjusting volume change of Sb 2 S 3 during storage Na + but also acted as a reducing agent assisting to create graphene aerogel. Moreover, the formation of unique Sb 2 S 3 @N-C coaxial nanotubes was facilitated by the N-C layer, which triggered the strong interaction between the Sb 2 S 3 and graphene to maintain structural integrity. Importantly, the composite aerogel synergized the superior electrical conductivity, abundant porous channels, and excellent electrochemical reactivity into one. As a result, the optimized anode exhibited high reversible capacity, superior rate capability, and impressively cycling stability. Furthermore, the full cell was constructed from the optimized composite aerogel anode and Na 3 V 2 (PO 4 ) 3 cathode, exhibiting a high reversible capacity of 388 mA h g −1 at 0.1 A g −1 with a remarkable energy density of 189 Wh kg −1 .