Ramie Degumming Waste-Derived Nitrogen and Molybdenum Dual-Doped Porous Carbon for High-Performance Lithium–Sulfur Batteries

Abstract

The high energy density and low cost of sulfur make lithium–sulfur batteries one of the most promising candidates for the next generation of energy storage. Nevertheless, the application is still hampered by the shuttle effect of soluble lithium polysulfides (LiPSs) intermediates and slow redox kinetics, resulting in irreversible loss of the active material, severe self-discharge and poor cycle stability of the electrode. Therefore, in this work, a novel Mo,N co-doped porous carbon (Mo,N−C) was successfully synthesized by simply calcining a mixture of ramie degumming waste with cost-effective molybdenum salt, and then employed as the LiPSs anchor. Due to the conductive carbon matrix, abundant porous structures as well as the doping Mo and N heteroatoms, the sluggish redox kinetic of the cathode has been significantly improved and the shuttle phenomenon of LiPSs has been effectively inhibited, consequently, the as-prepared Mo,N−C/S-0.4 composite cathode could demonstrate a good initial capacity of 1379.2 mAh g⁻¹ at 0.2 C, and the reversible capacity could remain at 997.5 mAh g⁻¹ after 100 cycles. Even at a high discharge rate of 1.0 C, the capacity could remain at 700.2 mAh g⁻¹ after 400 cycles. This work provides a new avenue for utilizing waste biomass in clean energy storage.