Lithium-sulfur battery is a promising energy storage system due to its high theoretical energy density and low cost. Unfortunately, it still suffers from poor cycling life and low coulombic efficiency caused by the shuttling effect of lithium polysulfides. Herein, we designed a nitrogen-doped hierarchical porous carbon host (NHPC) for physical and chemical confinement of polysulfides to effectively reduce the shuttling effect. This NHPC was prepared by a simple one-step pyrolysis process using low-cost ascorbic acid as the carbon source, melamine as the nitrogen source and Zn(NO₃)₂ as the pore generating and carbon exfoliation agent. The resulted NHPC was found to possess randomly stacked ultrathin holy carbon sheets, high BET surface area and pore volume, rich micro- and meso-pores and enriched nitrogen doping. When infiltrated with sulfur, the resulted NHPC/S material was found to exhibit excellent electrochemical cycling performance. It delivered a high initial capacity of 1200 mAh/g at 0.2 C, a reversible capacity of 729 mAh/g after 300 cycles at 1.0 C and excellent cycling stability with a capacity decay of only 0.057% per cycle after 300 cycles at 1.0 C. This work demonstrated a facile and efficient route to synthesize nitrogen-doped hierarchical porous carbon host for immobilization of sulfur in Li–S battery technology.

锂硫电池具有较高的理论能量密度和较低的成本，是一种很有前途的储能系统。不幸的是，由于锂多硫化物的穿梭作用，它仍然遭受循环寿命低和库仑效率低的困扰。本文中，我们设计了一种氮掺杂的分级多孔碳主体（NHPC），用于物理和化学限制多硫化物，以有效降低穿梭效应。通过低成本的抗坏血酸作为碳源，三聚氰胺作为氮源和Zn（NO ₃）₂的简单一步热解工艺制备了这种NHPC。作为造孔剂和碳剥落剂。发现所得的NHPC具有随机堆叠的超薄圣碳薄板，高BET表面积和孔体积，丰富的微孔和中孔以及丰富的氮掺杂。当用硫渗透时，发现所得的NHPC / S材料表现出优异的电化学循环性能。它在0.2 C下提供了1200 mAh / g的高初始容量，在1.0 C下进行了300次循环后可逆容量为729 mAh / g，并且具有出色的循环稳定性，在1.0 C下进行300次循环后每个循环的容量衰减仅为0.057％。这项工作证明了一种简便而有效的方法，可以合成用于Li-S电池技术中固定硫的氮掺杂的分级多孔碳主体。