Biomass-derived hierarchical carbon as sulfur cathode stabilizing agent for lithium-sulfur batteries

High surface area, biomass-derived carbon has been prepared by means of chemical activation of waste fruit peels with potassium carbonate and investigated as novel sulfur cathode component for lithium-sulfur batteries As evidenced by scanning electron microscopy and nitrogen absorption isotherms, the synthesized material features hierarchical micro-macroporous structure with sponge-like arrangement of interconnected microfilaments. Composite sulfur cathode fabricated with the application of this carbon has been shown to exhibit a very large initial specific discharge capacity of 886 mAh g(-1), at 0.1 C current rate, which remained remarkably stable over subsequent 50 charge/discharge cycles (capacity loss <1%). Excellent reversibility and cyclic stability of this composite cathode has been attributed to a unique combination of micro and macroporosity, as well as surface chemistry, allowing for the retention of the intermediate polysulfides within the carbon framework, without excessive dissolution in the bulk of electrolyte. (C) 2016 Elsevier B.V. All rights reserved.