Three-Dimensional Flower-Shaped Activated Porous Carbon/Sulfur Composites as Cathode Materials for Lithium–Sulfur Batteries

Abstract

In this study, three-dimensional flower-shaped activated porous carbon/sulfur composites (FA-PC/S) are fabricated for the first time via a simple method utilizing flower-shaped ZnO as a template and pitch as the carbon precursor, followed by carbonization activation and thermal treatment. The composites are characterized using scanning electron microscopy (SEM), transmission electron microscopy (TEM), Brunauer–Emmett–Teller (BET) analysis, Raman spectroscopy, X-ray powder diffraction (XRD), and thermogravimetric (TG) measurements. The results show that sulfur is well dispersed and encapsulated homogeneously in the micropores of the flower-shaped activated porous carbon (FA-PC) with excellent electrical conductivity, high surface area, and large pore volume. The electrochemical tests show that the FA-PC/S composites with 60 wt % S have a high initial discharge capacity of 1388 mA h g–1 at 100 mA g–1, good cycling stability (reversible discharging capacity of approximately 600 mA h g–1 at 1600 mA g–1), and excellent rate capability.