1T-MoS2 grown on amorphous carbon-coated carbon nanotubes for high-performance lithium-sulfur batteries

Abstract

Since lithium-sulfur batteries (LSBs) own large energy density, low cost, and environmental friendliness, they are recognized as the most up-and-coming energy storage devices. However, the low conductivity of sulfur and the shuttle effect of intermediate lithium polysulfides (LiPSs) greatly cause capacity decline. Herein, we synthesize a one-dimensional nanocomposite, in which metallic 1T-MoS2 with a large layer spacing is grown onto the amorphous carbon-coated carbon nanotubes (CNTs@C) via a facile solvothermal method, which is named as CNTs@C@1T-MoS2. The powerful interaction between the polar 1T-MoS2 and LiPSs severely weakens the shuttling effect. The CNTs@C@1T-MoS2 combines high catalytic activity of the 1T-MoS2 with high electronic conductivity of the CNTs, resulting in faster reaction kinetics. Therefore, lithium-sulfur battery assembled with CNTs@C@1T-MoS2-modified separator exhibits an initial discharge capacity of 1373 mAh/g at 0.2 C, and delivers a discharge capacity of 691 mAh/g after 400 cycles at 1 C. This work provides a simple method to obtain multi-functional separators for high-performance LSBs, and this method can also be applied to other rechargeable battery systems, such as Na/S, Mg/S, K/S, Al/S, Zn/S, and Li/Se batteries.