A Highly Ordered Meso@Microporous Carbon-Supported Sulfur@Smaller Sulfur Core–Shell Structured Cathode for Li–S Batteries

Abstract

For lithium–sulfur batteries, commercial application is hindered by the insulating nature of sulfur and the dissolution of the reaction intermediates of polysulfides. Here, we present an ordered meso-microporous core–shell carbon (MMCS) as a sulfur container, which combines the advantages of both mesoporous and microporous carbon. With large pore volume and highly ordered porous structure, the “core” promises a sufficient sulfur loading and a high utilization of the active material, while the “shell” containing microporous carbon and smaller sulfur acts as a physical barrier and stabilizes the cycle capability of the entire S/C composite. Such a S/MMCS composite exhibits a capacity as high as 837 mAh g^–1 at 0.5 C after 200 cycles with a capacity retention of 80% vs the second cycle (a decay of only 0.1% per cycle), demonstrating that the diffusion of the polysulfides into the bulk electrolyte can be greatly reduced. We believe that the tailored highly ordered meso-microporous core–shell structured carbon can also be applicable for designing some other electrode materials for energy storage