Cobalt-doped oxygen-deficient titanium dioxide coated by carbon layer as high-performance sulfur host for Li/S batteries

Yuan Tian, Xiao Zhang, Yongguang Zhang, Jingde Li, Aizhong Jia, Guihua Liu, Zhumabay Bakenov

Research output: Contribution to journalArticlepeer-review

Abstract

The severe shuttle effect and sluggish conversion kinetics of lithium polysulfides impede the commercialization of lithium/sulfur (Li/S) batteries. To address this issue, a composite consists of Co-doped oxygen-deficient TiO2 coated by carbon layer (Co/TiO2-x@carbon) is proposed as a high-performance sulfur host. It was fabricated by one-step hydrothermal synthesis, follow by chemical vapor deposition method. The oxygen defects on the surface of Co/TiO2-x@carbon enhanced its electrical conductivity and strengthened the chemical interactions with polysulfides toward superior sulfur confinement. Moreover, the carbon coating layer has a hollow spherical architecture that can accelerate electron or ion transportation. Additionally, the Co nanoparticles promote sulfur redox conversion. Benefiting from these synergistic features, the S/Co/TiO2-x@carbon electrode delivers outstanding cycling stability (the capacity decay rate of 0.044% per cycle after 500 cycles) and a superior rate performance (972 mAh g−1 at 2.0C).

Original languageEnglish
Article number157969
JournalJournal of Alloys and Compounds
Volume861
DOIs
Publication statusAccepted/In press - 2020

Keywords

  • Co-doped
  • Lithium/sulfur batteries
  • Oxygen vacancy
  • Titanium dioxide

ASJC Scopus subject areas

  • Mechanics of Materials
  • Mechanical Engineering
  • Metals and Alloys
  • Materials Chemistry

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