Self-Standing Lotus Root-Like Host Materials for High-Performance Lithium-Sulfur Batteries

The structure of sulfur host materials plays a key role in alleviating the shuttle effect, volume expansion and sluggish redox reaction of lithium-sulfur batteries (LSBs). In this work, the well-designed multichannel carbon fibers decorated by carbon nanotubes (CNTs) and CoS nanoparticles (MCF/CoS/CNT) are synthesized and serve as the flexible sulfur host. The in situ grown CNTs network and embedded CoS enhance the overall conductivity of electrode and facilitate the redox reaction of sulfur-related electrochemistry. Benefitting from these merits, the MCF/CoS/CNT-based cathode exhibits a high reversible capacity of 927 mAh g(-1)after 180 cycles with a low decay of 0.034% per cycle at 1.0 C. A superb areal capacity of 5.2 mAh cm(-2) could be obtained under a high sulfur loading of 6.3 mg cm(-2) and an ultralow electrolyte/sulfur ratio of 6.5 mu L mg(-1)after 100 cycles. This work offers a promising approach to the reasonable design of flexible sulfur host for LSBs toward high energy density.

Automated summary

The structure of sulfur host materials is crucial for improving the performance of lithium-sulfur batteries. In this study, a flexible sulfur host composed of well-designed multichannel carbon fibers decorated with carbon nanotubes and CoS nanoparticles was synthesized. The incorporation of carbon nanotubes and CoS into the host material enhanced the overall conductivity and facilitated the redox reaction of sulfur-related electrochemistry. The results demonstrated high reversible capacity and superb areal capacity, making this approach promising for high energy density lithium-sulfur batteries.