Anchoring function for polysulfide ions of ultrasmall SnS2 in hollow carbon nanospheres for high performance lithium-sulfur batteries

Tin sulfide-anchored sulfur-hollow carbon nanospheres (S/AHCNS-SnS2) composites are synthesized by uniformly dispersing conductive SnS2 particles into hollow carbon nanospheres activated with potassium hydroxide, followed by impregnating sulfur. Surface morphology and structure of this composite are characterized using a field emission scanning electron microscopy (FESEM), field emission transmission electron microscopy (FETEM), Brunauer-Emmett-Teller (BET) method, X-ray power diffraction (XRD) and X-ray photoelectron spectroscopy (XPS). The first discharge capacity of the sample containing 10 wt.% SnS2 exhibits a high special capacity value of about 1237.5 mAh g(-1) at 0.2C, and after 200 cycles retains 924 mAh g(-1). Tin sulfide particles play a favorable role on adsorption towards polysulfides which would influence electrochemical process. This strategy of immobilization of sulfur with small amount of metal sulfide particles anchored in AHCNS provides a considerable approach to elevate the sulfur loading, coulombic efficiency, and cycling stability for Li-S batteries. (C) 2015 Elsevier B.V. All rights reserved.