Preparation of Sb@N/F Co-Doped Carbon Nanocomposites and Their Sodium Storage Properties

Abstract

Antimony (Sb) -based materials with high theoretical capacity (660mAh g-1) and suitable sodium ion embedding potentials are considered as one of the promising anode materials for sodium-ion batteries, which is expected to improve the low capacity of sodium-ion batteries. However, its volume expansion during the charge/discharge process is evident, thus failing to stabilize its capacity advantage. Herein, nanosized Sb particles are induced to form. by introducing N/F co-doped carbon nanosheets (NF-CNs) during the liquid phase reduction process, which alleviates the volume expansion phenomenon of Sb and prevents Sb aggregation and pulverization during the charge/discharge process. Secondly, the Sb nanoparticles can contact with the electrolyte solution sufficiently and shorten the ion diffusion route, thus improving the kinetic characteristics of the material. The introduced carbon matrix not only prevents agglomeration of Sb nanoparticles during the cycling process, but also provides a highly conductive pathway for the rapid ion and electron transfer. Based on the above optimization, the sodium storage performance of the Sb@NF-CNs anode is significantly improved, and the assembled sodium-ion battery has a reversible capacity of 304. 7mAh g-1 after 50 cycles at the current density of 0. 1A g-1 and a reversible capacity of 163mAh g-1 after 200 cycles at the current density of 1. 0A g-1 with excellent rate performance.