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

Abstract

The Sb2S3 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 Sb2S3@nitrogen-doped carbon (Sb2S3@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 Sb2S3 nanorods. The PDA was not only a precursor of nitrogen-doped carbon (N-C) layer adjusting volume change of Sb2S3 during storage Na+ but also acted as a reducing agent assisting to create graphene aerogel. Moreover, the formation of unique Sb2S3@N-C coaxial nanotubes was facilitated by the N-C layer, which triggered the strong interaction between the Sb2S3 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 Na3V2(PO4)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.