Electrochemical Characterization of Single-Walled Carbon Nanotube Electrodes

Abstract

Carbon nanotubes are of significant interest due to their unique properties and potential applications. [1][2][3][4] We are interested in using single-walled carbon nanotubes (SWNTs) as an electrode material suitable for electromechanical actuators. 5 Such application requires a good understanding of the electrochemical properties of SWNTs.In this initial report, we describe some of the basic electrochemical characteristics of sheets of SWNTs. These sheets, called nanotube paper (NTP) due to their appearance, consist of SWNT bundles joined by mechanical entanglement and van der Waals interactions. The NTP shows high porosity and large surface area. 5,6 It is generally considered 1-6 that in the material used the nanotubes ends are closed and that the interstitial spaces between individual nanotubes inside a bundle are not accessible to the electrolyte. Consequently, the pores responsible for most of the surface area correspond to the void spaces between bundles. The techniques utilized for the characterization of the NTP were cyclic voltammetry, electrochemical impedance spectroscopy, and electrochemical quartz crystal microgravimetry. Several aqueous and nonaqueous electrolytes were evaluated.Experimental Chemicals and materials.-All solutions were prepared using Milli-Q deionized water. The SWNTs dispersed in water were obtained from Tubes@Rice (Rice University) with a purity better than 90%. The material consists of hexagonally packed bundles of nanotubes 1.2-1.4 nm diam. Each bundle consists of about 30 nanotubes and is 10 nm average diam and several micrometers long. 6

A review of electrode materials for electrochemical supercapacitors

“…High surface area carbon materials mainly include activated carbon, [82][83][84][85][86][87] carbon aerogels, 88 carbon nanotubes (CNTs), 89,90 templated porous carbons, [91][92][93][94] and carbon nanofibres. 95 The performance of these carbons as ES electrode materials has been described in detail in the literature.…”

Artificial Muscle Technology: Physical Principles and Naval Prospects

“…As in conducting polymers, it is the rate at which charge can be injected which determines tlie strain rate. The enormous internal surface area provided by the carbon nanotubes results in an enormous capacitance (26 F/g) [73]. Given the applied potentials are on the order of 1 V, the resulting charge transfer is ~ 26 C/g.…”

Fabrication of CNT/CMK3 Carbon Composites with High Electrical/Thermal Conductive Properties

“…[13][14][15][16][17][18] The CNT electrodes exhibit unique pore structures and high use efficiency of specific surface areas. 15,17 The CNT electrodes for EDLCs have excellent absorption characteristics owing to the accessible mesopores formed by the entangled individual CNTs.…”