Aligned TiO₂ nanotube/nanoparticle heterostructures with enhanced electrochemical performance as three-dimensional anode for lithium-ion microbatteries

Nanotechnology. 2014 Nov 14;25(45):455401. doi: 10.1088/0957-4484/25/45/455401. Epub 2014 Oct 22.

Abstract

A novel TiO₂ three-dimensional (3D) anode with an aligned TiO₂ nanotube/nanoparticle heterostructure (TiO₂ NTs/NPs) is developed by simply immersing as-anodized TiO₂ NTs into water and further crystallizing the TiO₂ NTs by post-annealing. The heterostructure, with its core in a tubular morphology and with both the outer and inner surface consisting of nanoparticles, is confirmed by FESEM and TEM. A reversible areal capacity of 0.126 mAh · cm(-2) is retained after 50 cycles for the TiO₂ NTs/NPs heterostructure electrode, which is higher than that of the TiO₂ NTs electrode (0.102 mAh · cm(-2) after 50 cycles). At the current densities of 0.02, 0.04, 0.06, 0.08, 0.10 and 0.20 mA · cm(-2), the areal capacities are 0.142, 0.127, 0.117, 0.110, 0.104 and 0.089 mAh · cm(-2), respectively, for the TiO₂ NTs/NPs heterostructure electrode compared to the areal capacities of 0.123, 0.112, 0.105, 0.101, 0.094 and 0.083 mAh · cm(-2), respectively, for the the TiO₂ NTs electrode. The enhanced electrochemical performance is attributed to the unique microstructure of the TiO₂ NTs/NPs heterostructure electrode with the TiO₂ NT core used as a straight pathway for electronic transport and with TiO₂ NP offering enhanced surface areas for facile Li+ insertion/extraction. The results described here inspire a facile approach to fabricate a 3D anode with an enhanced electrochemical performance for lithium-ion microbattery applications.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Electric Power Supplies
  • Electrochemistry
  • Ions / chemistry
  • Lithium / chemistry*
  • Nanoparticles / chemistry*
  • Nanotubes / chemistry*
  • Nickel / chemistry*
  • Particle Size
  • Surface Properties
  • Titanium / chemistry*

Substances

  • Ions
  • titanium dioxide
  • Nickel
  • Lithium
  • Titanium