Cobalt-loaded three-dimensional mesoporous carbon as sulfur host for lithium‑sulfur batteries

The practical application of lithium‑sulfur batteries has been limited due to the poor electrical conductivity of sulfur, the shuttling effect of polysulfide, and the slow redox kinetics of sulfur species. Designing a multifunctional sulfur host with good conductivity, strong adsorption, and high catalytic activity could effectively address these issues. In this work, the cobalt nanoparticles-loaded three-dimensional mesoporous carbon (Co-TDMC) composite was developed as the multifunctional host for lithium‑sulfur batteries. Due to its large specific surface area (2404.7 m2 g−1), abundant mesopores, and good-catalytic performance, the composite could effectively contain sulfur, adsorb polysulfide, and accelerates the conversion reaction of sulfur species. Therefore, when Co-TDMC was used as the sulfur carrier, the sulfur cathode had an excellent initial discharge capacity (1403 mAh g−1 at 0.1C) and a good rate performance (780.2 mAh g−1 at 1C)·In addition, it has excellent long-term cycling stability (a low decay rate of 0.06 % per cycle during 500 cycles at 1C). This work provides a feasible strategy for improving the cycle stability of lithium‑sulfur batteries. [Display omitted] •Three-dimensional porous structure with a hightspecific surface area (2404.7 m2 g−1)•Cobalt nanoparticles are firmly embedded in the graphitized carbon layer.•Co-TDMC accelerates polysulfide conversion.