High‐Surface‐Area Nitrogen/Phosphorus Dual‐Doped Hierarchical Porous Carbon Derived from Biochar for Sulfur Holder

Abstract

AbstractBiomass jellyfish umbrellas are used to prepare N,P‐codoped activated carbon (denoted as NPAC) through a soaking in NH4H2PO4 solution and activation process by potassium hydroxide. The key features of NPAC materials are the micro‐/mesopore coexistent structure and ultrahigh surface area (2307 m2 g−1), which displays the significance of carbon synthesis from biochars. When NPAC serves as the sulfur holder, it not only benefits the maximum encapsulation of sulfur in the pores but also restrains the dissolution of polysulfides through physisorption. Meanwhile, the N and P co‐doping is favorable for binding polysulfides by providing additional chemical adsorption sites via bonding with polysulfides. Relying on the synergistic effect of physi‐/chemisorption, the sulfur‐infiltrated NPAC material (NPAC−S) shows superior electrochemical performance to AC−S. After 300 cycles at a high current density of 1 C, the NPAC−S72 composite indicates a reversible capacity of 517 mAh g−1 with the capacity decay of 0.103% per cycle after 300 cycles. This work demonstrates that the biomass‐derived carbon route promises due to the unexpected textures of the as‐obtained carbon materials inherently from the special biological structures. The NPAC also shows a promising prospect in the application of absorbents, electrochemical catalysts, and capacitor materials, which inspires researcher to explore other new functional carbonaceous materials.