Ultrafine Sb2S3@carbon-nanofibers for fast and stable sodium storage

Abstract

Sb2S3 has great theoretical capacity (946 mAh g−1), suitable working potential, and relatively low cost, and it has attracted attention as a potential anode material for sodium-ion batteries. However, the tardy diffusion of sodium ions and significant volume expansion hinder their practical application in sodium ion batteries. In this study, we encapsulated Sb2S3 nanoparticles in porous carbon nanofibers (CNFs) using electrospinning and gas vulcanization. The unique porous fiber structure and ultrafine Sb2S3 nanoparticles effectively improved diffusion speed and volume expansion of sodium ions, and they showed fast sodium-ion storage capacity and excellent cycle stability. The Sb2S3@CNFs used as the anode of a sodium-ion battery exhibited a remarkably reversible specific capacity of 151.3 mAh g−1 at 10 A g−1 for 500 cycles. A full cell assembled with Sb2S3@CNFs and Na3V2(PO4)3 (NVP) showed a reversible specific capacity of 283 mAh g−1 at 0.2 A g−1 after 100 cycles. Therefore, Sb2S3@CNFs has an excellent practical application in sodium-ion batteries owing to its simple synthesis method, excellent electrochemical performance, and suitable reaction potential.