Abstract
Hollow Co3O4 nanosphere aggregate/N-doped graphitic carbon (HCO/NGC) composite powders, exhibiting excellent Li-ion storage performances, were prepared by applying metal–organic frameworks (MOFs). Zeolitic imidazolate framework (ZIF)-67 cubes were reduced to produce Co/NGC composite powders. The Co/NGC composite powders were oxidized to produce cubic HCO/NGC composite powders, in which the hollow Co3O4 nanospheres were uniformly covered with a NGC layer. The Co nanocrystals transformed into hollow nanospheres during oxidation via the nanoscale Kirkendall diffusion process. The unique composite structure accommodates mechanical stress owing to the void spaces within the Co3O4 nanospheres; it also prevents structure collapse during cycling owing to the presence of the NGC matrix. Thus, the cubic hollow powders exhibited excellent electrochemical performances when used as an anode material in Li-ion batteries (LIBs). Following 250 cycles, the HCO/NGC composite powders with 11 wt% NGC delivered a discharge capacity of 1030 mA h g− 1 at a current density of 1 A g− 1. In addition, the composite powders delivered a discharge capacity of 738 mA h g− 1 even at a high current density of 10 A g− 1.
Original language | English |
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Pages (from-to) | 320-329 |
Number of pages | 10 |
Journal | Materials Characterization |
Volume | 132 |
DOIs | |
Publication status | Published - 2017 Oct |
Bibliographical note
Funding Information:This work was supported by a Korea University Grant.
Publisher Copyright:
© 2017 Elsevier Inc.
Keywords
- Cobalt oxide
- Graphitic carbon
- Hollow structure
- Kirkendall effect
- Lithium-ion batteries
- Metal-organic framework
ASJC Scopus subject areas
- General Materials Science
- Condensed Matter Physics
- Mechanics of Materials
- Mechanical Engineering