Synthesis of a Macroporous Conjugated Polymer Framework: Iron Doping for Highly Stable, Highly Efficient Lithium-Sulfur Batteries

Pan Jia, Tianding Hu, Qingbin He, Xiao Cao, Junpeng Ma, Jingbiao Fan, Quan Chen, Yihong Ding, Jeffrey Pyun, Jianxin Geng

Research output: Contribution to journalArticle

16 Scopus citations

Abstract

Porous conjugated polymers offer enormous potential for energy storage because of the combined features of pores and extended π-conjugated structures. However, the drawbacks such as low pore volumes and insolubilities of micro- and mesoporous conjugated polymers restrict the loading of electroactive materials and thus energy storage performance. Herein, we report the synthesis of iron-doped macroporous conjugated polymers for hosting sulfur as the cathode of high-performance lithium-sulfur (Li-S) batteries. The macroporous conjugated polymers are synthesized via in situ growth of poly(3-hexylthiophene) (P3HT) from reduced graphene oxide (RGO) sheets, followed by gelation of the composite (RGO-g-P3HT) in p-xylene and freeze-drying. The network structures of the macroporous materials can be readily tuned by controlling the chain length of P3HT grafted to RGO sheets. The large pore volumes of the macroporous RGO-g-P3HT materials (ca. 34 cm 3 g -1 ) make them excellent frameworks for hosting sulfur as cathodes of Li-S batteries. Furthermore, incorporation of Fe into the macroporous RGO-g-P3HT cathode results in reduced polarization, enhanced specific capacity (1,288, 1,103, and 907 mA h g -1 at 0.05, 0.1, and 0.2 C, respectively), and improved cycling stability (765 mA h g -1 after 100 cycles at 0.2 C). Density functional theory calculations and in situ characterizations suggest that incorporation of Fe enhances the interactions between lithium polysulfides and the P3HT framework.

Original languageEnglish (US)
Pages (from-to)3087-3097
Number of pages11
JournalACS Applied Materials and Interfaces
Volume11
Issue number3
DOIs
StatePublished - Jan 23 2019

Keywords

  • SI-KCTP
  • graphene
  • iron doping
  • lithium-sulfur batteries
  • macroporous conjugated polymer

ASJC Scopus subject areas

  • Materials Science(all)

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