Design of a Metal–Organic Framework‐Derived Co9S8/S Material for Achieving High Durability and High Performance of Lithium–Sulfur Batteries

Abstract Enhancing the durability and performance of high‐energy‐density lithium–sulfur batteries (LSBs) is of paramount important for energy storage. We have fabricated a metal–organic framework‐derived (MOF) Co 9 S 8 /S (cobalt sulfide/sulfur) modified separator in LSBs which displays highest durability and excellent performance. The material successfully suppresses polysulfide shuttling, which is a determining factor in the deterioration of performance and lifetime of a battery. The Co 9 S 8 /S material is derived from a Co‐MOF. Its porosity and structural features make it an efficient material for capturing lithium polysulfides (LiPS), which is involved in chemical interactions with polarities within Co 9 S 8 /S. The kinetics of redox reactions involving LiPS are facilitated by the conductive properties of the material. A prolonged cycle life of 2000 charge–discharge cycles at a 1 C‐rate is observed when Co 9 S 8 /S is applied to the surface of a separator in the LSBs. An excellent discharge capacity of 879 mAh g −1 with the coulombic efficiency being maintained above 85 % throughout the course of 2000 charge–discharge cycles at a 1 C‐rate is achieved. Our strategy results in a material with unpresented high stability and durability of a MOF‐derived material which have fundamental importance in industrial and future commercialization of LSBs.