Flexible and Self-Supported Sulfur Cathode for High-Energy-Density Lithium-Sulfur Batteries

Abstract

For developing lithium-sulfur (Li-S) batteries, it is critical to design and synthesis advanced cathode materials with high sulfur loading, utilization ratios and strong binding interactions with sulfur species to prevent the ‘shuttle effect’ of electrolyte soluble intermediate polysulfides. Self-supported nanoarrays with hierarchical void and rich reaction sites are promising for advanced electrodes high-performance Li-S batteries. Here we report an effective sulfur host material prepared by integrating sulfur, carbon cloth, and CoP covered metal organic framework-derived N-doped carbon nanoarrays. These polar covered nanoarrays with a unique structure possess not only offer the enough void for volume expansion to maintain the structural stability during the electrochemical process, but also promote the physical encapsulation and chemical entrapment for all sulfur species. As a result, the CC@CoP/C electrodes with a high sulfur loading and display a high specific capacity at different current densities and long-term cycling performance (e.g. 600 cycles at 2C with an ultra-low capacity decay of 0.016% per cycle).