Carbon Nanofibers with Embedded Sb 2 Se 3 Nanoparticles as Highly Reversible Anodes for Na-Ion Batteries

As a promising candidate for large-scale energy storage, sodium-ion batteries (SIBs) have superiority due to their low cost and abundance as a resource. Herein, homogeneous Sb2 Se3 nanocrystallites embedded in carbon nanofibers (Sb2 Se3 /CNFs) by electrospinning and selenization treatment are prepared. The obtained Sb2 Se3 /CNFs exhibit good cycling performance, high reversible capacity, and excellent rate capability as anodes for SIBs. The outstanding performances are attributed to a combination of Na+ intercalation, conversion reaction, and alloying with Sb2 Se3 , disclosed through in-situ X-ray diffraction. Meanwhile, unique nanostructures provide large contact surface and tolerant accommodation to volume expansion which bring high reversibility and long cycle durability. This distinctive material shows prospective applications of SIBs especially under high current density.