Lithium Sulfide-Embedded Three-Dimensional Heterogeneous Micro-/Mesoporous Interwoven Carbon Architecture as the Cathode of Lithium-Sulfur Batteries

摘要

Lithium sulfide (Li2S)-oriented cathodes of lithium-sulfur batteries (LSBs) are intensively studied in virtue of their high energy density, outstanding charge/discharge characteristics, and safety. In this study, Li2S is embedded in a three-dimensional (3D) micro-/mesoporous carbon architecture with a tunable internal structure, low density, suitable void volume, and pore size via carbonization. The mesoporous internal structure can offer considerable voids for volume change and a fast transfer route of charges and ions, and the microporous coating layer could physically block the shuttle of polysulfides and accommodate the diffusion of Li+ ions. The results show that the as-fabricated Li2S/CMK3/C has a high lithium sulfide loading of 79 wt %. At the same time, the battery delivers a high specific capacity of 848 mA h g(-1) at 0.1 C and a good capability of 410 mA h g(-1) after 400 cycles at 2 C. Therefore, the Li2S-embedded 3D micro-/mesoporous carbon architecture could be a significant option for the development and industrialization of high-performance LSBs.