Synthesis and Electrochemical Performance of Sulfur/Highly Porous Carbon Composites

Abstract

Sulfur/highly porous carbon (HPC) composites were synthesized by thermally treating a mixture of sublimed sulfur and HPC. The microstructure of the HPC and the composite was characterized by transmission electron microscopy (TEM), scanning electron microscopy (SEM), X-ray diffraction (XRD), and Brunauer-Emmett-Teller (BET) surface area. The specific surface area of HPC reaches up to 1472.9 m 2 /g, which is sharply reduced to 24.4 m 2 /g in the sulfur/HPC composite with 57 wt % sulfur. The electrochemical performance of the composites as cathode materials in organic electrolytes was studied by the galvanostatic method and cyclic voltammetry. The sulfur/HPC composite with 57 wt % sulfur delivers the initial high specific capacity up to 1155 mAh/g and a stable capacity of 745 mAh/g after 84 cycles at the current density of 40 mA/g. In addition, it is demonstrated that the excellent cycling stability of the sulfur/HPC composite can be obtained at different current densities. On the basis of the analysis of the microstructure and electrochemical performance, it is confirmed that HPC can effectively prevent the shuttle behavior of the lithium/sulfur battery.

Large-scale synthesis of ordered mesoporous carbon fiber and its application as cathode material for lithium–sulfur batteries

“…This suggests good dispersion of the S within the porous carbon host [31]. Raman spectra of OMCF, S, and OMCF-S composite were also carried out to further observe their structure in Fig.…”

Lithium–sulphur batteries with a microporous carbon paper as a bifunctional interlayer

“…Employing sulphur-carbon composites and applying conductive polymer surface modification are the main approaches in laboratories around the world to realize high capacity and improved cycle life [2][3][4][5][13][14][15][16][17][18][19][20] . Both approaches enhance the electrical conductivity of the cathode and suppress the loss of soluble polysulphide intermediates during cycling and thereby improve the active material utilization and cyclability.…”

TiO 2 coated three-dimensional hierarchically ordered porous sulfur electrode for the lithium/sulfur rechargeable batteries

“…The pure elemental sulfur has various diffraction peaks, corresponding to an orthorhombic structure. As for the C-S and C-S-TiO 2 composites, some diffraction peaks of the elemental S are visible, although the intensities become distinctly lower and some diffraction peaks even disappear, which suggests good dispersion of the S within the mesoporous carbon hosts [33]. The sulfur content in the C-S and C-S-TiO 2 composites was determined by thermogravimetric analysis (TGA) conducted under argon atmosphere (as shown in Fig.…”