Uniform decoration of vanadium oxide nanocrystals on reduced graphene-oxide balls by an aerosol process for lithium-ion battery cathode material

Seung Ho Choi, Yun Chan Kang

Research output: Contribution to journalArticle

36 Citations (Scopus)

Abstract

VO2-decorated reduced graphene balls were prepared by a one-pot spray-pyrolysis process from a colloidal spray solution of well-dispersed graphene oxide and ammonium vanadate. The graphene-VO2 composite powders prepared directly by spray pyrolysis had poor electrochemical properties. Therefore, the graphene-VO2 composite powders were transformed into a reduced graphene ball (RGB)-V2O5 (RGB) composite by post-treatment at 300 C in an air atmosphere. The TEM and dot-mapping images showed a uniform distribution of V and C components, originating from V2O5 and graphene, consisting the composite. The graphene content of the RGB-V2O5 composite, measured by thermogravimetric analysis, was approximately 5wt %. The initial discharge and charge capacities of RGB-V2O5 composite were 282 and 280mA h g-1, respectively, and the corresponding Coulombic efficiency was approximately 100 %. On the other hand, the initial discharge and charge capacities of macroporous V2O5 powders were 205 and 221mA h g-1, respectively, and the corresponding Coulombic efficiency was approximately 93 %. The RGB-V2O5 composite showed a better rate performance than the macroporous V2O5 powders. Graphene-based ball: V2O5-decorated reduced-graphene balls and macroporous V2O5 powders were prepared by a spray-pyrolysis process. The V2O5-decorated reduced-graphene balls had higher initial charge and discharge capacities and better cycling and rate performances than the macroporous V2O 5 powders (see figure).

Original languageEnglish
Pages (from-to)6294-6299
Number of pages6
JournalChemistry - A European Journal
Volume20
Issue number21
DOIs
Publication statusPublished - 2014 May 19

Keywords

  • electrochemistry
  • graphene
  • lithium-ion batteries
  • spray pyrolysis
  • vanadium

ASJC Scopus subject areas

  • Catalysis
  • Organic Chemistry

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