Sb/SnO@C composite prepared by electrospinning for high performance sodium ion battery anodes

Abstract

The development of high-performance anode material for sodium-ion batteries remains a challenge because of their low capacity, which limits their commercial application. Compared with carbon-based materials, metallic Sb and SnO-based anodes have received extensive attention because of their high theoretical specific capacity and safe working potential. The main problem faced is the serious volume expansion during charging and discharging, leading to irreversible loss of capacity and poor cycle life. In this paper, Sb/SnO@C composite material with adjustable ratio of Sb/SnO was prepared via electrospinning by encapsulating Sb and SnO particles in lantern-like carbon nanocages which connected through the nanofibers. The unique structure can not only effectively mitigate the volume changes during the cycle, but also provide multiple effective paths for ion and electron transport. The kinetic analysis is further performed with the assist of CV and EIS. The results show that the prepared composite can provide impressive Na+ ions storage and transport performance, and can still deliver a reversible charging capacity of 413mAhg−1 after 200 cycles at a current density of 50mAg−1, with a capacity retention ratio of 84%. This work provides a new strategy for the development of sodium ion batteries with high capacity and stable cycle performance.