Conductive vanadium-based metal-organic framework nanosheets membranes as polysulfide inhibitors for lithium-sulfur batteries

Abstract

The polysulfide shuttle is regarded as the most critical challenge that hinders the commercial process of lithium-sulfur batteries (LSBs). Herein, a vanadium-based MIL-47 nanosheets membrane is fabricated on carbon nanotube film for this trouble, which serves as a versatile interlayer material in LSBs. With a good electrolyte wettability, thin thickness and appropriate pore diameter, MIL-47 nanosheets membrane is capable of efficaciously blocking polysulfides and enabling the fast transport of Li ions via the selectively sieving effect. Furthermore, the excellent conductivity and fully exposed catalytic metal centers contribute to enhance the reaction kinetics and sulfur utilization. Therefore, this MOF-based interlayer provides a wonderful capacity of 1044.6 mAh g−1 and a durable cyclic performance with a numbered decay of 0.03 % per cycle for 1000 cycles at 1 C. Even under harsh conditions of high sulfur loading and lean electrolyte, excellent cycle and rate performances are still acquired. This work boosts the development of multi-functional materials in LSBs.