N-doped carbon-coated hollow carbon nanofibers with interspersed TiO2 for integrated separator of Li-S batteries

Yuebin Yang, Hui Xu, Shanxing Wang, Yuanfu Deng, Xianying Qin, Xusong Qin, Guohua Chen

Research output: Journal article publicationJournal articleAcademic researchpeer-review

21 Citations (Scopus)

Abstract

Li-ion batteries have held a dominant position in the energy storage area for decades. However, due to the limitation of its chemistry, the energy density of Li-ion batteries is limited to ∼300 W h kg−1. In recent years, more attention has been paid to the Li-S batteries that are environmentally friendly, cost-effective and high energy density (theoretical value of cathode: ∼2600 W h kg−1). In this study, carbonized polydopamine (C-PDA)-coated hollow carbon nanofibers (CNFs) with TiO2 nanoparticles interspersed in the void space between the CNF skeleton and carbon coating layer were subtly designed. The C-PDA/TiO2/CNF composite (CTC) was integrated with the commercial separator as a polysulfide filter to achieve high-performance Li-S batteries. It is reveals that the CTC coating layer could effectively filter and reactivate the dissolved polysulfides to achieve a stabilized sulfur-based cathode. The Li-S battery assembled by this integrated separator and the regular cathode (sulfur/Ketjen black) with 72.7 wt% of sulfur achieved a high specific capacity and low decay rate (632.5 mAh g−1 at the first cycle and 0.06% per cycle) at 2.0C for 500 cycles. These good results indicate that the C-PDA/TiO2/CNF-modified separator could be a promising separator candidate for high performance Li-S batteries.

Original languageEnglish
Pages (from-to)641-649
Number of pages9
JournalElectrochimica Acta
Volume297
DOIs
Publication statusPublished - 20 Feb 2019

Keywords

  • Carbon nanofibers
  • Interlayer
  • Li-S batteries
  • Separator
  • TiO

ASJC Scopus subject areas

  • Chemical Engineering(all)
  • Electrochemistry

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