Sulfur impregnated in tunable porous N-doped carbon as sulfur cathode: Effect of pore size distribution

Sha Wang, Zhenxia Zhao, Hui Xu, Yuanfu Deng, Zhong Li, Guohua Chen

Research output: Journal article publicationJournal articleAcademic researchpeer-review

18 Citations (Scopus)

Abstract

Abstract A novel porous N-doped carbon microsphere (polymer-dopamine derived carbon, PDA-C) with high specific surface area was synthesized as sulfur host for high performance of lithium-sulfur batteries. We used KOH to adjust the pore size and surface area of the PDA-C materials, and then impregnated sulfur into the PDA-C samples by vapor-melting diffusion method. Effects of pore size of the PDA-C samples on the electrochemical performance of the PDA-C@sulfur cathodes were systematically investigated. Raman spectra indicated an enhanced trend of the degree of graphitization of the PDA-C samples with increasing calcination temperature. The surface area of the PDA-C samples increases with amount of the KOH in the pore-creating process. The graphitized porous N-doped carbon provides the high electronic conductive network. Meanwhile, the PDA-C with high surface area and uniform micropores ensures a high interaction toward sulfur as well as the high dispersion of nanoscale sulfur layer on it. The microporous PDA-C@S cathode material exhibits the excellent high rate discharge capability (636 mA h g-1 at 2.0 C) and good low/high-rate cycling stability (893 mA h g-1 (0.5 C) and 608 mA h g-1 (2.0 C) over 100 and 300 cycles). Cyclic voltammogram curves and electrochemical impedance plots show that both the impedance and polarization of the cells increase with decreasing pore size.
Original languageEnglish
Article number24963
Pages (from-to)282-289
Number of pages8
JournalElectrochimica Acta
Volume173
DOIs
Publication statusPublished - 10 Aug 2015
Externally publishedYes

Keywords

  • Lithium-sulfur battery
  • N-doped carbon
  • pore size
  • sulfur adsorption

ASJC Scopus subject areas

  • Chemical Engineering(all)
  • Electrochemistry

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