Effect of the size and position of ion-accessible nanoholes on the specific capacitance of single-walled carbon nanohorns for supercapacitor applications

Cheol Min Yang, Yong Jung Kim, Jin Miyawaki, Yoong Ahm Kim, Masako Yudasaka, Sumio Iijima, Katsumi Kaneko

Research output: Contribution to journalArticle

17 Citations (Scopus)

Abstract

We explore the importance of the size and position of nanoholes on the electrochemical performance of single-walled carbon nanohorn (SWCNH)-based supercapacitors using an ionic liquid electrolyte. The oxidized sample at 673 K showed a low specific capacitance per unit of internal specific surface area (4.0 μF cm-2), as the nanoholes created on the tips of SWCNHs via a selective chemical attack are too small to introduce electrolyte ions. For a sample oxidized at 723 K, the enlarged diameter of the nanoholes on the tips allows electrolyte ions to penetrate into the internal spaces of the SWCNHs, thereby resulting in a 2-fold capacitance improvement (8.6 μF cm-2). However, the abrupt decrease in the capacitance of the oxidized SWCNHs at 823 K (3.8 μF cm-2) can be explained by the selective formation of nanoholes on the sidewalls of the SWCNHs, where the small interstitial pores restrict ion diffusion to deeply positioned nanoholes on the sidewalls of the SWCNHs. Our study clearly reveals that the size and position of nanoholes with regard to ion accessibility are crucial factors to improve the capacitive performance of SWCNH-based supercapacitors.

Original languageEnglish
Pages (from-to)2935-2940
Number of pages6
JournalJournal of Physical Chemistry C
Volume119
Issue number6
DOIs
Publication statusPublished - Feb 12 2015

Fingerprint

Nanohorns
electrochemical capacitors
Capacitance
Carbon
capacitance
Ions
Electrolytes
carbon
electrolytes
ions
chemical attack
Chemical attack
Ionic Liquids
Ionic liquids
Specific surface area
interstitials
porosity
Supercapacitor
liquids

All Science Journal Classification (ASJC) codes

  • Electronic, Optical and Magnetic Materials
  • Energy(all)
  • Physical and Theoretical Chemistry
  • Surfaces, Coatings and Films

Cite this

Effect of the size and position of ion-accessible nanoholes on the specific capacitance of single-walled carbon nanohorns for supercapacitor applications. / Yang, Cheol Min; Kim, Yong Jung; Miyawaki, Jin; Kim, Yoong Ahm; Yudasaka, Masako; Iijima, Sumio; Kaneko, Katsumi.

In: Journal of Physical Chemistry C, Vol. 119, No. 6, 12.02.2015, p. 2935-2940.

Research output: Contribution to journalArticle

Yang, Cheol Min ; Kim, Yong Jung ; Miyawaki, Jin ; Kim, Yoong Ahm ; Yudasaka, Masako ; Iijima, Sumio ; Kaneko, Katsumi. / Effect of the size and position of ion-accessible nanoholes on the specific capacitance of single-walled carbon nanohorns for supercapacitor applications. In: Journal of Physical Chemistry C. 2015 ; Vol. 119, No. 6. pp. 2935-2940.
@article{964475f36e1246419b2d5ccd41b596c0,
title = "Effect of the size and position of ion-accessible nanoholes on the specific capacitance of single-walled carbon nanohorns for supercapacitor applications",
abstract = "We explore the importance of the size and position of nanoholes on the electrochemical performance of single-walled carbon nanohorn (SWCNH)-based supercapacitors using an ionic liquid electrolyte. The oxidized sample at 673 K showed a low specific capacitance per unit of internal specific surface area (4.0 μF cm-2), as the nanoholes created on the tips of SWCNHs via a selective chemical attack are too small to introduce electrolyte ions. For a sample oxidized at 723 K, the enlarged diameter of the nanoholes on the tips allows electrolyte ions to penetrate into the internal spaces of the SWCNHs, thereby resulting in a 2-fold capacitance improvement (8.6 μF cm-2). However, the abrupt decrease in the capacitance of the oxidized SWCNHs at 823 K (3.8 μF cm-2) can be explained by the selective formation of nanoholes on the sidewalls of the SWCNHs, where the small interstitial pores restrict ion diffusion to deeply positioned nanoholes on the sidewalls of the SWCNHs. Our study clearly reveals that the size and position of nanoholes with regard to ion accessibility are crucial factors to improve the capacitive performance of SWCNH-based supercapacitors.",
author = "Yang, {Cheol Min} and Kim, {Yong Jung} and Jin Miyawaki and Kim, {Yoong Ahm} and Masako Yudasaka and Sumio Iijima and Katsumi Kaneko",
year = "2015",
month = "2",
day = "12",
doi = "10.1021/jp510630e",
language = "English",
volume = "119",
pages = "2935--2940",
journal = "Journal of Physical Chemistry C",
issn = "1932-7447",
publisher = "American Chemical Society",
number = "6",

}

TY - JOUR

T1 - Effect of the size and position of ion-accessible nanoholes on the specific capacitance of single-walled carbon nanohorns for supercapacitor applications

AU - Yang, Cheol Min

AU - Kim, Yong Jung

AU - Miyawaki, Jin

AU - Kim, Yoong Ahm

AU - Yudasaka, Masako

AU - Iijima, Sumio

AU - Kaneko, Katsumi

PY - 2015/2/12

Y1 - 2015/2/12

N2 - We explore the importance of the size and position of nanoholes on the electrochemical performance of single-walled carbon nanohorn (SWCNH)-based supercapacitors using an ionic liquid electrolyte. The oxidized sample at 673 K showed a low specific capacitance per unit of internal specific surface area (4.0 μF cm-2), as the nanoholes created on the tips of SWCNHs via a selective chemical attack are too small to introduce electrolyte ions. For a sample oxidized at 723 K, the enlarged diameter of the nanoholes on the tips allows electrolyte ions to penetrate into the internal spaces of the SWCNHs, thereby resulting in a 2-fold capacitance improvement (8.6 μF cm-2). However, the abrupt decrease in the capacitance of the oxidized SWCNHs at 823 K (3.8 μF cm-2) can be explained by the selective formation of nanoholes on the sidewalls of the SWCNHs, where the small interstitial pores restrict ion diffusion to deeply positioned nanoholes on the sidewalls of the SWCNHs. Our study clearly reveals that the size and position of nanoholes with regard to ion accessibility are crucial factors to improve the capacitive performance of SWCNH-based supercapacitors.

AB - We explore the importance of the size and position of nanoholes on the electrochemical performance of single-walled carbon nanohorn (SWCNH)-based supercapacitors using an ionic liquid electrolyte. The oxidized sample at 673 K showed a low specific capacitance per unit of internal specific surface area (4.0 μF cm-2), as the nanoholes created on the tips of SWCNHs via a selective chemical attack are too small to introduce electrolyte ions. For a sample oxidized at 723 K, the enlarged diameter of the nanoholes on the tips allows electrolyte ions to penetrate into the internal spaces of the SWCNHs, thereby resulting in a 2-fold capacitance improvement (8.6 μF cm-2). However, the abrupt decrease in the capacitance of the oxidized SWCNHs at 823 K (3.8 μF cm-2) can be explained by the selective formation of nanoholes on the sidewalls of the SWCNHs, where the small interstitial pores restrict ion diffusion to deeply positioned nanoholes on the sidewalls of the SWCNHs. Our study clearly reveals that the size and position of nanoholes with regard to ion accessibility are crucial factors to improve the capacitive performance of SWCNH-based supercapacitors.

UR - http://www.scopus.com/inward/record.url?scp=84923163231&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=84923163231&partnerID=8YFLogxK

U2 - 10.1021/jp510630e

DO - 10.1021/jp510630e

M3 - Article

AN - SCOPUS:84923163231

VL - 119

SP - 2935

EP - 2940

JO - Journal of Physical Chemistry C

JF - Journal of Physical Chemistry C

SN - 1932-7447

IS - 6

ER -