MOF-derived LDH wrapped with rGO as an efficient sulfur host for lithium-sulfur batteries

Abstract

Lithium‑sulfur batteries (LSBs) have been continuously studied due to high theoretical specific capacity (1675 mAh g−1) and theoretical energy density (2600 Wh kg−1), making it the most competitive choice for new generation energy storage devices. However, the poor electronic conductivity of sulfur as an active material and the continuous shuttle effect of lithium polysulfides (LiPSs) limit the further application of LSBs. In this work, metal-organic framework (MOF)-derived layered double hydroxide (LDH) wrapped with reduced graphene oxide (rGO) is designed and prepared as an effective sulfur host for LSBs. Thanks to high specific surface area of LDH/rGO, the adsorption of LDH for LiPSs, and the excellent electronic conductivity of rGO, the electrochemical performance of S/LDH/rGO is greatly improved. The S/LDH/rGO delivers the first discharge capacity of 958 mAh g−1 at 0.2C with a Coulombic efficiency of 99%. Even at a high current density of 1C, the discharge capacity of the S/LDH/rGO still reaches to 730 mAh g−1 at the first cycle. The LDH/rGO is a potential sulfur host for LSBs.