Electrochemical charge-transfer resistance in carbon nanotube composites

Corso B. L., Perez I., Sheps T., Sims P. C., Guel O. T., Collins P. G.

Nano Letters, cilt.14, sa.3, ss.1329-1336, 2014 (SCI-Expanded) identifier identifier identifier

  • Yayın Türü: Makale / Tam Makale
  • Cilt numarası: 14 Sayı: 3
  • Basım Tarihi: 2014
  • Doi Numarası: 10.1021/nl404349g
  • Dergi Adı: Nano Letters
  • Derginin Tarandığı İndeksler: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Sayfa Sayıları: ss.1329-1336
  • Anahtar Kelimeler: Carbon nanotube, charge transfer, supercapacitor, heterogeneous composite, MANGANESE-DIOXIDE, ENERGY-STORAGE, HIGH-CAPACITY, SUPERCAPACITOR, ELECTRODES, PERFORMANCE, GRAPHITE, KINETICS, BEHAVIOR, NANOWIRES
  • Ankara Hacı Bayram Veli Üniversitesi Adresli: Hayır

Özet

Using a model system of single, isolated carbon nanotubes loaded with high-capacitance metal-oxide films, we have quantitatively investigated electrochemical composites on the single-nanotube scale. Electrochemical charging and discharging of a model MnO2 storage material was used to probe interfacial charge transfer and surface impedances at the nanotube interface. We found that one single-walled carbon nanotube has an apparent surface resistivity of 30 mΩ cm2, approximately 4 times smaller than for a multiwalled carbon nanotube and 50 times smaller than the 1.5 Ω cm2 resistivity of Pt or graphite films. The improvement originates in the electrochemical-transport properties of microelectrodes shrunk to a nanotube's dimensions rather than any unique nanotube property like curvature, bandstructure, or surface chemistry. In explaining the enhanced performance of certain nanotube-containing composites, the results overturn widely held assumptions about nanotubes' roles while also providing guidelines for optimizing effective composites. © 2014 American Chemical Society.