A Metal–Organic Framework with Open Metal Sites for Enhanced Confinement of Sulfur and Lithium–Sulfur Battery of Long Cycling Life

The lithium–sulfur battery has a very high theoretical capacity and specific energy density, yet its applications have been obstructed by fast capacity fading and low Coulombic efficiency due to the dissolution of polysulfides. Herein we utilize HKUST-1 as the host material to trap sulfur and thus to diminish the dissolution problem. A large amount of sulfur (40 wt %) has been incorporated in HKUST-1 pore metrics to achieve HKUST-1⊃S composite whose structure has been established by both single and powder X-ray diffraction studies. The strong confinement of HKUST-1 for sulfur attributed to the suitable pore spaces and open Cu2+ sites has enabled the resulting Li–S⊂HKSUT-1 battery to show excellent performance with a capacity of about 500 mAh/g after 170 cycles.