A novel carbon nanotubes@porous carbon/sulfur composite as efficient electrode material for high-performance lithium-sulfur battery

摘要

Herein, we reported a novel carbon nanotubes@porous carbon/sulfur (CNT@PC/S) composite with huge specific capacity for rechargeable lithium-sulfur battery. The porous carbon has a large surface area and appropriate pore size which derived from the aluminum-based metal-organic framework (Al-MOF). The obtained electrochemical results show the CNT@PC/S composite with 50% of sulfur content displays superior discharge specific capacity of 424 mAh g(-1) after 100 cycles at a rate of 0.5 C with a better coulombic efficiency of 98%. Furthermore, the optimized CNT@PC/S composite offered a large discharge specific capacity of 271.2 mAh g(-1) using ultra-fast rate of 2 C. The pore structure of CNT@PC encapsulates with the elemental sulfur, which is efficiently inhibiting the diffusion of polysulfide ions in electrolyte, resulting in the greatly improve the ability of volume changes during the charge-discharge process. Therefore, the as-prepared CNT@PC/S composite can be a talented cathode material for lithium-sulfur battery and other electrochemical devices.