Supercapacitor performance of vertically aligned multiwall carbon nanotubes produced by aerosol-assisted CCVD method

作者：Fedorovskaya E O^*; Bulusheva L G; Kurenya A G; Asanov I P; Rudina N A; Funtov K O; Lyubutin I S; Okotrub A V

来源：Electrochimica Acta, 2014, 139: 165-172.

DOI：10.1016/j.electacta.2014.06.176

• Vertically aligned carbon nanotubes
• Supercapacitor
• Cyclic voltammetry
• X-ray photoelectron spectroscopy
• Encapsulated iron
• Mossbauer spectroscopy

Arrays of vertically aligned carbon nanotubes (CNTs) grown on n-doped silicon substrates using an aerosol-assisted catalytic chemical vapor deposition (CCVD) technique have been tested as supercapacitor electrodes. Electrochemical properties of the electrodes were shown to be significantly dependent on the array thickness. At scan rate of 20 mV/s the largest specific capacitance of 124 F/g was achieved for the similar to 280-mu m array, while increase in the thickness to similar to 1100 mu m caused a drop in electrode capacitance by four times. It was shown that in a sulfuric acid electrolyte, the redox processes with iron nanoparticles encapsulated in CNTs contribute significantly to the capacitance of array. From the Mossbauer spectroscopy, these nanoparticles are present as alpha-Fe, gamma-Fe, and Fe3C phases. X-ray photoelectron spectroscopy revealed that during the electrode charging and discharging sulfates of Fe(II) and Fe(III) are formed in surficial layers of the nanoparticles.

• 出版日期2014-9-1