Honeycomb‐like Nitrogen and Sulfur Dual‐Doped Hierarchical Porous Biomass‐Derived Carbon for Lithium–Sulfur Batteries

Abstract

Abstract Honeycomb‐like nitrogen and sulfur dual‐doped hierarchical porous biomass‐derived carbon/sulfur composites (NSHPC/S) are successfully fabricated for high energy density lithium–sulfur batteries. The effects of nitrogen, sulfur dual‐doping on the structures and properties of the NSHPC/S composites are investigated in detail by transmission electron microscopy (TEM), X‐ray photoelectron spectroscopy (XPS), X‐ray diffraction (XRD), and charge/discharge tests. The results show that N, S dual‐doping not only introduces strong chemical adsorption and provides more active sites but also significantly enhances the electronic conductivity and hydrophilic properties of hierarchical porous biomass‐derived carbon, thereby significantly enhancing the utilization of sulfur and immobilizing the notorious polysulfide shuttle effect. Especially, the as‐synthesized NSHPC‐7/S exhibits high initial discharge capacity of 1204 mA h g −1 at 1.0 C and large reversible capacity of 952 mA h g −1 after 300 cycles at 0.5 C with an ultralow capacity fading rate of 0.08 % per cycle even at high sulfur content (85 wt %) and high active material areal mass loading (2.8 mg cm −2 ) for the application of high energy density Li–S batteries.