Molybdenum disulfide (MoS2)/porous silica nanosheet composite barrier for polysulfide shuttling inhibition in lithium-sulfur batteries

Abstract

Lithium-sulfur batteries (LSBs) is the key choice for the next generation of high energy density batteries, while the shuttle effect of polysulfides greatly limits its development. Constructing a multifunctional barrier layer has been proved to be an effective method to inhibit the shuttle of polysulfides. Herein, molybdenum disulfide (MoS2)/2D porous silica nanosheets (PSN) composite is designed as the barrier layer. The surface oxygen-containing groups on both PSN and MoS2 enhance the adsorption for LiPSs, and the MoS2 plays a role of catalyst to facilitate the rapid polysulfide transformation. Meanwhile the abundant pores of PSN guide the uniform deposition of lithium on lithium metal anode, finally realizing the efficient transformation of lithium polysulfides and inhibition of lithium dendrites. The LSBs based on the MoS2/PSN barrier deliver high initial discharge capacity of 1521 mAh g−1 at 0.1 C, low decay rate of 0.056% per cycle at 2 C over 600 cycles, and outstanding rate performance with a high discharge capacity of 649 mAh g−1 at 4 C. The corresponding pouch cells show high discharge capacity and cycling stability, further demonstrating the potential application of the composite barrier in high-energy-density LSBs.