Novel cobalt oxide-nanobubble-decorated reduced graphene oxide sphere with superior electrochemical properties prepared by nanoscale Kirkendall diffusion process

Gi Dae Park, Jung Sang Cho, Yun Chan Kang

Research output: Contribution to journalArticle

62 Citations (Scopus)


In this study, a novel metal oxide-reduced graphene oxide (RGO) composite structure, denoted as a "nanobubble-decorated RGO sphere," was fabricated and characterized for potential use in Li+-ion batteries. The nanobubble-decorated RGO sphere consists of an RGO sphere uniformly decorated with hollow metal oxide nanopowder. Reduction of the composite powder prepared by spray pyrolysis under H2/Ar gas mixture formed RGO spheres decorated with metal nanopowders. The metal nanopowders were transformed into hollow metal oxide nanopowders, or nanobubbles, by the nanoscale Kirkendall diffusion process. Cobalt oxide nanobubble-decorated RGO spheres, prepared as the first target material, showed excellent Li-storage properties. The cobalt oxide-RGO composite powders, tested at the current density of 2Ag-1 for 200 cycles before and after the nanoscale Kirkendall diffusion, showed discharge capacities of 932 and 1156mAhg-1, respectively; their capacity retentions measured from the second cycle onward were 89% and 99%, respectively.

Original languageEnglish
Pages (from-to)17-26
Number of pages10
JournalNano Energy
Publication statusPublished - 2015 Jan 1



  • Graphene composite
  • Kirkendall diffusion
  • Lithium ion battery
  • Spray pyrolysis

ASJC Scopus subject areas

  • Renewable Energy, Sustainability and the Environment
  • Materials Science(all)
  • Electrical and Electronic Engineering

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