Nitrogen-sulfur dual-doped citric-acid porous carbon as host for Li-S batteries

A nitrogen-sulfur dual-doped citric-acid porous carbon/sulfur (NS-CAPC/S) materials was prepared by an easy hydrothermal method applying glutathione as nitrogen-sulfur origin and citric-acid carbon as carbon origin. The detailed structure of the materials was determined through raman spectroscopy, X-ray photoelectron spectroscopy, and X-ray diffraction tests. The appearance of the materials was investigated via transmission electron microscopy and scanning electron microscopy methods. N2 adsorption–desorption isotherm was applied to test its pore size distribution and pore structure. Thermogravimetric analysis (TGA) was utilized to identify the mass ratio of sulfur. The NS-CAPC/S materials was employed as positive electrode material in Li-S batteries. Electrochemical performance revealed the prepared NS-CAPC/S composite possessed good specific capacity, exceptionally high cycle stability and excellent rate performance.