| Lithium-sulfur (Li-S) batteries have attracted researchers’ attention due to its high specific capacity and large energy density. It is considered as one of the most promising next-generation secondary batteries. In spite of the above advantages, it still faces with several challenges to develop the Li-S batteries, including the low conductivity of sulfur and Li2S/Li2S2, poor cycle performance and rate performance, which derives from the shuttle effect. It needs to solve these problems for the application of Li-S batteries.Tin sulfide-anchored sulfur-hollow carbon nanospheres (S/AHCNS-SnS2) composites and Copper-anchored sulfur-hollow carbon nanosphere are synthesized by uniformly dispersing conductive SnS2 (or Cu) 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 0.2 C, and after 200 cycles retains 924 mAh g-1.The first discharge capacity of the sample with copper nanoparticles exhibits a high special capacity value of about 1164.7 mAh g-1 at 0.2 C, and after 200 cycles retains 841 mAh g-1. Tin sulfide particles (or copper nanoparticles) 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 or metal particles anchored in AHCNS provides an considerable approach to elevate the sulfur loading, coulombic efficiency, and cycling stability for Li-S batteries. |
PDF Full Text Request