Carbon Nanofibres Confined SnS Nanostructure with High Flexibility and Enhanced Performance for Sodium-Ion Batteries

Abstract

Stannous sulfide (SnS) still faces the challenge of damatic volume changes during discharge/charge processes, which results in the appearance of fractures and pulverization in the electrode and rapid capacity attenuation of the sodium-ion batteries (SIBs). To handle this issue, we construct a N doped carbon nanofibres (N-CNFs) confined SnS nanostructure (SnS/N-CNFs) by embedding SnS nanoparticles into N-CNFs during the calcination of electrospun nanofibres and directly used as an anode for SIBs. The formed carbon structure of electrospun nanofibers confines the growth of SnS, promotes the homogeneous dispersion of SnS and prevents volume effect of SnS during the charge and discharge process in SIBs. Moreover, the SnS/N-CNFs are interconnected to become a three-dimensional (3D) network, thus reveals high flexibility to tolerate 180° repeated bending and bear hundreds of times heavier than itself. In addition, the SnS/N-CNFs also forms an interconnected 3D conductive network. Benefiting from the confinement of N doped carbon nanofibers, the SnS/N-CNFs delivers a high capacity and excellent cycle performance of 422 mAh g^-1 at a current density 100 mA g^-1 after 150 cycles and maintains reversible capacity of 292 mAh g^-1 even at high current density of 500 mA g^-1. The outstanding flexibility and enhanced electrochemical performance demonstrate the free-standing SnS/N-CNFs material is a potential anode for flexible SIBs.

Keywords: electrospinning, N doped carbon nanofiber, SnS nanoparticles, sodium-ion batteries, flexible electrodes