Research Papers

Ion Storage in Nanoconfined Interstices Between Vertically Aligned Nanotubes in Electric Double-Layer Capacitors

[+] Author and Article Information
Aniruddha Dive

School of Mechanical and Materials Engineering,
Washington State University,
Pullman, WA 99164-2920

Soumik Banerjee

School of Mechanical and Materials Engineering,
Washington State University,
Pullman, WA 99164-2920
e-mail: soumik.banerjee@wsu.edu

1Corresponding author.

Manuscript received May 31, 2017; final manuscript received August 10, 2017; published online September 19, 2017. Assoc. Editor: Kevin Huang.

J. Electrochem. En. Conv. Stor. 15(1), 011001 (Sep 19, 2017) (8 pages) Paper No: JEECS-17-1060; doi: 10.1115/1.4037582 History: Received May 31, 2017; Revised August 10, 2017

Ionic liquids are considered promising electrolytes for developing electric double-layer capacitors (EDLCs) with high energy density. To identify optimal operating conditions, we performed molecular dynamics simulations of N-methyl-N-propyl pyrrolidinium bis(trifluoromethanesulfonyl)imide (mppy+ TFSI) ionic liquid confined in the interstices of vertically aligned carbon nanostructures mimicking the electrode structure. We modeled various surface charge densities as well as varied the distance between nanotubes in the array. Our results indicate that high-density ion storage occurs within the noninteracting double-layer region formed in the nanoconfined domain between charged nanotubes. We determined the specific arrangement of these ions relative to the nanotube surface and related the layered configuration to the molecular structure of the ions. The pitch distance of the nanotube array that enables optimal mppy+ TFSI storage and enhanced capacitance is determined to be 16 Å.

Copyright © 2018 by ASME
Your Session has timed out. Please sign back in to continue.


Burke, A. , 2000, “ Ultracapacitors: Why, How, and Where Is the Technology,” J. Power Sources, 91(1), pp. 37–50. [CrossRef]
Liu, C. , Li, F. , Ma, L. P. , and Cheng, H. M. , 2010, “ Advanced Materials for Energy Storage,” Adv. Mater., 22(8), pp. E28–E62. [CrossRef] [PubMed]
Tarascon, J. M. , and Armand, M. , 2001, “ Issues and Challenges Facing Rechargeable Lithium Batteries,” Nature, 414(6861), pp. 359–367. [CrossRef] [PubMed]
Meyyappan, M. , 2013, “ Nanostructured Materials for Supercapacitors,” J. Vac. Sci. Technol., A, 31(5), p. 050803. [CrossRef]
Winter, M. , and Brodd, R. J. , 2004, “ What Are Batteries, Fuel Cells, and Supercapacitors?,” Chem. Rev., 104(10), pp. 4245–4269. [CrossRef] [PubMed]
Feng, G. , Li, S. , Atchison, J. S. , Presser, V. , and Cummings, P. T. , 2013, “ Molecular Insights Into Carbon Nanotube Supercapacitors: Capacitance Independent of Voltage and Temperature,” J. Phys. Chem. C, 117(18), pp. 9178–9186. [CrossRef]
Aslan, M. , Weingarth, D. , Jaeckel, N. , Atchison, J. S. , Grobelsek, I. , and Presser, V. , 2014, “ Polyvinylpyrrolidone as Binder for Castable Supercapacitor Electrodes With High Electrochemical Performance in Organic Electrolytes,” J. Power Sources, 266, pp. 374–383. [CrossRef]
Shah, S. I. U. , Hector, A. L. , and Owen, J. R. , 2014, “ Redox Supercapacitor Performance of Nanocrystalline Molybdenum Nitrides Obtained by Ammonolysis of Chloride- and Amide-Derived Precursors,” J. Power Sources, 266, pp. 456–463. [CrossRef]
Hong, W. , Wang, J. , Niu, L. , Sun, J. , Gong, P. , and Yang, S. , 2014, “ Controllable Synthesis of CoAl LDH@Ni(OH)2 Nanosheet Arrays as Binder-Free Electrode for Supercapacitor Applications,” J. Alloys Compd., 608, pp. 297–303. [CrossRef]
Dyatkin, B. , Presser, V. , Heon, M. , Lukatskaya, M. R. , Beidaghi, M. , and Gogotsi, Y. , 2013, “ Development of a Green Supercapacitor Composed Entirely of Environmentally Friendly Materials,” ChemSusChem, 6(12), pp. 2269–2280. [CrossRef] [PubMed]
Gao, Y. , Presser, V. , Zhang, L. , Niu, J. J. , McDonough, J. K. , Perez, C. R. , Lin, H. , Fong, H. , and Gogotsi, Y. , 2012, “ High Power Supercapacitor Electrodes Based on Flexible TiC-CDC Nano-Felts,” J. Power Sources, 201, pp. 368–375. [CrossRef]
Fu, C. , Kuang, Y. , Huang, Z. , Wang, X. , Yin, Y. , Chen, J. , and Zhou, H. , 2011, “ Supercapacitor Based on Graphene and Ionic Liquid Electrolyte,” J. Solid State Electrochem., 15(11–12), pp. 2581–2585. [CrossRef]
Tamailarasan, P. , and Ramaprabhu, S. , 2012, “ Carbon Nanotubes-Graphene-Solidlike Ionic Liquid Layer-Based Hybrid Electrode Material for High Performance Supercapacitor,” J. Phys. Chem. C, 116(27), pp. 14179–14187. [CrossRef]
Lu, W. , Qu, L. , Henry, K. , and Dai, L. , 2009, “ High Performance Electrochemical Capacitors From Aligned Carbon Nanotube Electrodes and Ionic Liquid Electrolytes,” J. Power Sources, 189(2), pp. 1270–1277. [CrossRef]
Kotz, R. , and Carlen, M. , 2000, “ Principles and Applications of Electrochemical Capacitors,” Electrochim. Acta, 45(15–16), pp. 2483–2498. [CrossRef]
Abadi, P. P. S. S. , Maschmann, M. R. , Mortuza, S. M. , Banerjee, S. , Baur, J. W. , Graham, S. , and Cola, B. A. , 2014, “ Reversible Tailoring of Mechanical Properties of Carbon Nanotube Forests by Immersing in Solvents,” Carbon, 69, pp. 178–187. [CrossRef]
In, H. J. , Kumar, S. , Shao-Horn, Y. , and Barbastathis, G. , 2006, “ Origami Fabrication of Nanostructured, Three-Dimensional Devices: Electrochemical Capacitors With Carbon Electrodes,” Appl. Phys. Lett., 88(8), p. 083104. [CrossRef]
Chen, P.-C. , Shen, G. , Sukcharoenchoke, S. , and Zhou, C. , 2009, “ Flexible and Transparent Supercapacitor Based on In2O3 Nanowire/Carbon Nanotube Heterogeneous Films,” Appl. Phys. Lett., 94(4), p. 043113. [CrossRef]
Zhou, R. , Meng, C. , Zhu, F. , Li, Q. , Liu, C. , Fan, S. , and Jiang, K. , 2010, “ High-Performance Supercapacitors Using a Nanoporous Current Collector Made From Super-Aligned Carbon Nanotubes,” Nanotechnology, 21(34), p. 345701. [CrossRef] [PubMed]
Chen, T. , Peng, H. , Durstock, M. , and Dai, L. , 2014, “ High-Performance Transparent and Stretchable All-Solid Supercapacitors Based on Highly Aligned Carbon Nanotube Sheets,” Sci. Rep., 4(1), p. 3612. [CrossRef] [PubMed]
Yu, D. , Goh, K. , Wang, H. , Wei, L. , Jiang, W. , Zhang, Q. , Dai, L. , and Chen, Y. , 2014, “ Scalable Synthesis of Hierarchically Structured Carbon Nanotube-Graphene Fibres for Capacitive Energy Storage,” Nat. Nanotechnol., 9(7), pp. 555–562. [CrossRef] [PubMed]
Candelaria, S. L. , Shao, Y. , Zhou, W. , Li, X. , Xiao, J. , Zhang, J.-G. , Wang, Y. , Liu, J. , Li, J. , and Cao, G. , 2012, “ Nanostructured Carbon for Energy Storage and Conversion,” Nano Energy, 1(2), pp. 195–220. [CrossRef]
An, K. H. , Kim, W. S. , Park, Y. S. , Moon, J. M. , Bae, D. J. , Lim, S. C. , Lee, Y. S. , and Lee, Y. H. , 2001, “ Electrochemical Properties of High-Power Supercapacitors Using Single-Walled Carbon Nanotube Electrodes,” Adv. Funct. Mater., 11(5), pp. 387–392. [CrossRef]
Ma, R. Z. , Liang, J. , Wei, B. Q. , Zhang, B. , Xu, C. L. , and Wu, D. H. , 1999, “ Study of Electrochemical Capacitors Utilizing Carbon Nanotube Electrodes,” J. Power Sources, 84(1), pp. 126–129. [CrossRef]
Niu, C. M. , Sichel, E. K. , Hoch, R. , Moy, D. , and Tennent, H. , 1997, “ High Power Electrochemical Capacitors Based on Carbon Nanotube Electrodes,” Appl. Phys. Lett., 70(11), pp. 1480–1482. [CrossRef]
Frackowiak, E. , Metenier, K. , Pellenq, R. , Bonnamy, S. , and Beguin, F. , 1999, “ Capacitance Properties of Carbon Nanotubes,” 13th International Winterschool on Electronic Properties of Novel Materials (IWEPNM), Kirchberg, Austria, Feb. 27–Mar. 6, pp. 429–432.
Diederich, L. , Barborini, E. , Piseri, P. , Podesta, A. , Milani, P. , Schneuwly, A. , and Gallay, R. , 1999, “ Supercapacitors Based on Nanostructured Carbon Electrodes Grown by Cluster-Beam Deposition,” Appl. Phys. Lett., 75(17), pp. 2662–2664. [CrossRef]
An, K. H. , Jeon, K. K. , Heo, J. K. , Lim, S. C. , Bae, D. J. , and Lee, Y. H. , 2002, “ High-Capacitance Supercapacitor Using a Nanocomposite Electrode of Single-Walled Carbon Nanotube and Polypyrrole,” J. Electrochem. Soc., 149(8), pp. A1058–A1062. [CrossRef]
Zhang, H. , Cao, G. , Yang, Y. , and Gu, Z. , 2008, “ Comparison Between Electrochemical Properties of Aligned Carbon Nanotube Array and Entangled Carbon Nanotube Electrodes,” J. Electrochem. Soc., 155(2), pp. K19–K22. [CrossRef]
Brandt, A. , Pohlmann, S. , Varzi, A. , Balducci, A. , and Passerini, S. , 2013, “ Ionic Liquids in Supercapacitors,” MRS Bull., 38(7), pp. 554–559. [CrossRef]
Shim, Y. , and Kim, H. J. , 2010, “ Nanoporous Carbon Supercapacitors in an Ionic Liquid: A Computer Simulation Study,” ACS Nano, 4(4), pp. 2345–2355. [CrossRef] [PubMed]
Pak, A. J. , Paekw, E. , and Hwang, G. S. , 2013, “ Relative Contributions of Quantum and Double Layer Capacitance to the Supercapacitor Performance of Carbon Nanotubes in an Ionic Liquid,” Phys. Chem. Chem. Phys., 15(45), pp. 19741–19747. [CrossRef] [PubMed]
Shim, Y. , Jung, Y. , and Kim, H. J. , 2011, “ Graphene-Based Supercapacitors: A Computer Simulation Study,” J. Phys. Chem. C, 115(47), pp. 23574–23583. [CrossRef]
Mostafa, M. , and Banerjee, S. , 2014, “ Effect of Functional Group Topology of Carbon Nanotubes on Electrophoretic Alignment and Properties of Deposited Layer,” J. Phys. Chem. C, 118(21), pp. 11417–11425. [CrossRef]
Mostafa, M. , and Banerjee, S. , 2014, “ Predictive Model for Alignment and Deposition of Functionalized Nanotubes Using Applied Electric Field,” J. Appl. Phys., 115(24), p. 244309. [CrossRef]
Yang, L. , Fishbine, B. H. , Migliori, A. , and Pratt, L. R. , 2009, “ Molecular Simulation of Electric Double-Layer Capacitors Based on Carbon Nanotube Forests,” J. Am. Chem. Soc., 131(34), pp. 12373–12376. [CrossRef] [PubMed]
Plimpton, S. , 1995, “ Fast Parallel Algorithms for Short-Range Molecular-Dynamics,” J. Comput. Phys., 117(1), pp. 1–19. [CrossRef]
Jorgensen, W. L. , and Tiradorives, J. , 1988, “ The OPLS Potential Functions for Proteins—Energy Minimizations for Crystals of Cyclic-Peptides and Crambin,” J. Am. Chem. Soc., 110(6), pp. 1657–1666. [CrossRef] [PubMed]
Jorgensen, W. L. , Maxwell, D. S. , and TiradoRives, J. , 1996, “ Development and Testing of the OPLS All-Atom Force Field on Conformational Energetics and Properties of Organic Liquids,” J. Am. Chem. Soc., 118(45), pp. 11225–11236. [CrossRef]
Deshpande, A. , Kariyawasam, L. , Dutta, P. , and Banerjee, S. , 2013, “ Enhancement of Lithium Ion Mobility in Ionic Liquid Electrolytes in Presence of Additives,” J. Phys. Chem. C, 117(48), pp. 25343–25351. [CrossRef]
Nose, S. , and Klein, M. L. , 1983, “ Constant Pressure Molecular-Dynamics for Molecular-Systems,” Mol. Phys., 50(5), pp. 1055–1076. [CrossRef]
Nose, S. , 1984, “ A Unified Formulation of the Constant Temperature Molecular-Dynamics Methods,” J. Chem. Phys., 81(1), pp. 511–519. [CrossRef]
Pilon, L. , Wang, H. , and d'Entremont, A. , 2015, “ Recent Advances in Continuum Modeling of Interfacial and Transport Phenomena in Electric Double Layer Capacitors,” J. Electrochem. Soc., 162(5), pp. A5158–A5178. [CrossRef]
Borodin, O. , and Smith, G. D. , 2006, “ Structure and Dynamics of N-Methyl-N-Propylpyrrolidinium Bis(Trifluoromethanesulfonyl)Imide Ionic Liquid From Molecular Dynamics Simulations,” J. Phys. Chem. B, 110(23), pp. 11481–11490. [CrossRef] [PubMed]


Grahic Jump Location
Fig. 1

(a) A cross-sectional view of the x–y plane, perpendicular to the axes of the CNTs, of the simulation domain is shown with emphasis on the ions that constitute the double-layer around the CNTs. The distance between the surfaces of the nanotubes is defined as the pitch and is varied at 12 Å, 16 Å, and 20 Å. (b) A three-dimensional view of the simulation domain comprising the CNTs and ionic liquid ions is shown. (c) Structures of the mppy+ ion (top) and TFSI ion(bottom) are shown.

Grahic Jump Location
Fig. 2

The variation of number density of nitrogen of mppy+ [N(mppy+)] and nitrogen of TFSI [N(TFSI)] in the radial direction is shown for the system 25 TF. The reference distance R = 0 corresponds to the axis of the positively charged CNTs. Three distinct pitches of (a) 12 Å, (b) 16 Å, and (c) 20 Å were analyzed, and the distributions are shown to a maximum limit Rmax that corresponds to the axis of symmetry between two adjacent nanotubes.

Grahic Jump Location
Fig. 3

The variation of number density of nitrogen of mppy+ [N(mppy+)] and nitrogen of TFSI [N(TFSI)] in the radial direction is shown for the system 25 MP. The reference distance R = 0 corresponds to the axis of the negatively charged CNTs. Three distinct pitches of (a) 12 Å, (b) 16 Å, and (c) 20 Å were analyzed, and the distributions are shown to a maximum limit Rmax that corresponds to the axis of symmetry between two adjacent nanotubes.

Grahic Jump Location
Fig. 4

The variation of number density of hydrogen atom of mppy+ [H(mppy+)] and N(mppy+) for the system 25 MP at a pitch of 20 Å is shown

Grahic Jump Location
Fig. 5

The RDF for N(mppy+) (denoted as N+) with respect to N(TFSI) (denoted as N) is shown for the system 25 TF at different pitches

Grahic Jump Location
Fig. 6

Number density of (a) N(TFSI) and (b) N(mppy+) for the systems with positively charged CNTs, 5 TF and 25 TF, with pitch of 20 Å is presented

Grahic Jump Location
Fig. 7

Number density of (a) N(TFSI) and (b) N(mppy+) for the systems with negatively charged CNTs, 5 MP and 25 MP, with pitch of 20 Å is presented

Grahic Jump Location
Fig. 8

Average electrostatic potential difference for CNT with surface charge density of (a) +0.08 C/m2 and (b) −0.08 C/m2 is presented for various CNT arrays



Some tools below are only available to our subscribers or users with an online account.

Related Content

Customize your page view by dragging and repositioning the boxes below.

Related Journal Articles
Related eBook Content
Topic Collections

Sorry! You do not have access to this content. For assistance or to subscribe, please contact us:

  • TELEPHONE: 1-800-843-2763 (Toll-free in the USA)
  • EMAIL: asmedigitalcollection@asme.org
Sign In