配向性炭素ナノチューブの電気化学的エネルギー変換デバイスへの展開 (<特集>2003年度実施の地域との共同研究の報告)
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概要
- 論文の詳細を見る
Carbon nanotubes ( CNTs ) are attracting worldwide attention as hydrogen electrodes/suppliers toelectrochemical energy storage devices, such as fuel cells, and super capacitors, to come true theenvironmental friendly world. However, several kinetic problems of CNT electrode remain to besolved before practical use is possible. In this study, the film electrodes of vertically aligned multiwallcarbon nanotube ( MWNT ) synthesized by catalytic chemical vapor deposition were employedfor electrochemical hydrogen charging/discharging experiments, to correctly evaluate the electrodeperformances and to better understand the electrode kinetics. The current-potential curves duringcharging/discharging were studied using cyclic voltammetry. A clear reproducible anodic peak forthe oxidation of hydrogen in the electrode was found between -0.9 V and -0.7 V. The heat treatmentsat 400℃ under the air atmosphere produced significant changes in the anodic peak whose behaviorreflects electrochemical kinetic properties and hydrogen storage capacity. The electrochemicalimpedance spectroscopy measurements were conducted successfully on the electrodes under thepotentiodynamic polarization at the scan rate of 0.1 mV/s. The impedance spectra consisted of a smallsemicircle at high frequencies and a large depressed semicircle at low frequencies. Around the -0.85V, the total reaction resistance reached a minimum. An equivalent circuit for the aligned MWNTelectrode was proposed to elucidate the reaction mechanism for electrochemical hydrogen charging/discharging.
- 室蘭工業大学の論文
- 2004-11-30