Flexible free-standing SnS2/carbon nanofibers anode for high performance sodium-ion batteries

To solve the problems of insufficient conductivity and volume expansion of SnS2 during cycling when applied as anode for sodium-ion batteries (SIBs), we designed flexible and self-standing SnS2/carbon nanofibers (SnS2/CNFs) film by electrospinning technology and post sulfuration, in which the ultrafine SnS2 nanoparticles (∼5 nm) are preganated in the carbon nanofibers. The three-dimensional carbon nanofibers serve as flexible scaffold with high electrical conductivity to buffer the aggregation and pulverization of SnS2 particles. The obtained flexible SnS2/CNFs film can be directly used as anode for SIBs without adding binder and carbon additive, and exhibits excellent electrochemical performance. The SnS2/CNFs delivers a high capacity of 570.8 mAh g−1 at 0.2 A g−1. Even at a high rate of 5 A g−1, a high capacity of 247.1 mAh g−1 is still achieved. It also maintains 378.9 mAh g−1 after 100 cycles at 0.5 A g−1.