A simple SDS-assisted self-assembly method for the synthesis of hollow carbon nanospheres to encapsulate sulfur for advanced lithium-sulfur batteries

The hollow carbon nanospheres (HCNSs) were prepared using a simple SDS-assisted self-assembly method, and a sulfur-carbon composite based on HCNSs was synthesized for lithium-sulfur batteries by a vapor phase infusion method. The sulfur-HCNS composite was characterized by X-ray diffraction (XRD), field emission scanning electron microscopy (SEM), transmission electron microscopy (TEM), and thermogravimetry (TG) measurements. It is found that the elemental sulfur was dispersed inside the pores of carbon spheres. It is demonstrated from the galvanostatic discharge-charge process and cyclic voltammetry (CV) that the sulfur-HCNS composite has a large reversible capacity and an excellent cycling performance as cathode materials. The sulfur-HCNS composite with a sulfur content of 47.6 wt% displays an initial discharge capacity of 1031 mA h g(-1) and a reversible discharge capacity of 477 mA h g(-1) after 100 cycles at 0.5 C charge-discharge rate.