Built-in ultrafine CoS2 catalysis in confined ordered micro-mesoporous carbon nanoreactors for high-performance Li–S batteries

Constructing high-performance cathode host materials which can eliminate the dissatisfactory utilization of sulfur, the sluggish redox kinetics, and the lithium polysulfide (LiPSs) shuttle effect is highly desirable for the development of lithium-sulfur (Li–S) batteries. Recently, the porous carbon nanoreactors have received significant attention owing to unique spatial structure and customizable reaction sites. Whereas, the disordered pore distribution as well as surface catalysis in these hosts still restrict the performance of Li–S batterie. Herein, a synthesis of built-in ultrafine CoS2 catalysis in confined ordered micro-mesoporous carbon (OMMC) nanoreactors is proposed to accelerate LiPSs conversion. Due to high surface areas, protective OMMC shell, great electronic conductivity, and high-efficiency active sites, the synthetic nanoreactor shows exceptional physical confinement, satisfactory chemical anchoring, as well as excellent electrocatalysis for LiPSs. As expected, the S/CoS2@OMMC cathodes achieved excellent cyclic stability (615 mAh g−1 at 1.0 C after 1000 cycles with an ultralow capacity decay of 0.032% per cycle) and outstanding rate performance (655 mAh g−1 at 5.0 C).