SnO2\ nanoparticles confined by N-doped and CNTs-modified carbon fibers as superior anode material for sodium-ion battery

In the present work, carbon nanofibers (CNFs) decorated with carbon nanotubes (CNTs) and SnO2 nanoparticles (SnO2@CNFs/CNTs) were synthesized through electrospinning technique and following thermal treatment. Due to the flexible fibrous structure of composite, the as-obtained mats can be directly utilized as free-standing anodes for SIBs. Thanks to the in-situ introduced CNTs, the harsh carbonization treatment condition can be simplified. In addition, excellent electrochemical performances were obtained when the optimized composite was applied as anodes for SIBs. Specifically, a discharge capacity of 460.3 mAh g(-1) can be maintained after 200 cycles. Besides, 222.2 mAh g(-1) can be delivered even at a high current density of 3.2 A g(-1). These results demonstrate that the as-obtained anodes possess a highly stable cycling performance and excellent rate capabilities. The approach we proposed shows great prospect for practical application.