• 文献标题:   A porous nitrogen and phosphorous dual doped graphene blocking layer for high performance Li-S batteries
  • 文献类型:   Article
  • 作  者:   GU XX, TONG CJ, LAI C, QIU JX, HUANG XX, YANG WL, WEN B, LIU LM, HOU YL, ZHANG SQ
  • 作者关键词:  
  • 出版物名称:   JOURNAL OF MATERIALS CHEMISTRY A
  • ISSN:   2050-7488 EI 2050-7496
  • 通讯作者地址:   Griffith Univ
  • 被引频次:   135
  • DOI:   10.1039/c5ta04255k
  • 出版年:   2015

▎ 摘  要

Conductive confinement of sulfur and polysulfides via carbonaceous blocking layers can simultaneously address the issues of low conductivity, volume expansion of sulfur during the charge/discharge process and the polysulfide shuttling effect in lithium-sulfur (Li-S) batteries. Herein, a conductive and porous nitrogen and phosphorus dual doped graphene (p-NP-G) blocking layer is prepared via a thermal annealing and subsequent hydrothermal reaction route. The doping levels of N and P in p-NP-G as measured by X-ray photoelectron spectroscopy are ca. 4.38% and ca. 1.93%, respectively. The dual doped blocking layer exhibits higher conductivity than N or P single doped blocking layers. More importantly, density functional theory (DFT) calculations demonstrate that P atoms and -P-O groups in the p-NP-G layer offer stronger adsorption of polysulfides than the N species. The electrochemical evaluation results illustrate that the p-NP-G blocking layer can deliver superior initial capacity (1158.3 mA h g(-1) at a current density of 1C), excellent rate capability (633.7 mA h g-1 at 2C), and satisfactory cycling stability (ca. 0.09% capacity decay per cycle), which are better than those of the N or P single doped graphene. This work suggests that this synergetic combination of conductive and adsorptive confinement strategies induced by the multi-heteroatom doping scheme is a promising approach for developing high performance Li-S batteries.