Low-Cost Synthetic Honeycomb-like Carbon Derived from Cotton as a Sulfur Host for the Enhanced Electrochemical Performances of Lithium-Sulfur Batteries

摘要

Lithium-sulfur batteries with high-energy density are witnessed to be the most prospective next-generation advanced batteries. Nonetheless, the existing issues of the serious shuttle effect and insulating property restrict their further applications. Herein, a honeycomb-like porous carbon derived from cotton is designed and prepared as a sulfur host to overcome the abovementioned problems. The cotton carbon carbonized at 700 degrees C acquires plentiful mesopores/macropores and displays a high surface area (458.85 m(2) g(-1)). The C/S composite shows a relatively high capacity of 1271 mAh g(-1) for the first cycle at 100 mA g(-1). The carbon treated at 600 degrees C possesses abundant carbon-oxygen groups, which is beneficial for chemical adsorption of soluble polysulfides. The high-sulfur-loading (74 wt %) C/S electrode exhibits long-span cycling stability over 200 cycles. Benefiting from the excellent conductivity of cross-linked carbon fibers and the unique porous structure for trapping sulfur as well as the polysulfides, the cotton C/S composites exhibit superior properties for advanced lithium-sulfur batteries.