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Molecular Insights into Aqueous NaCl Electrolytes Confined within Vertically-oriented Graphenes

Vertically-oriented graphenes (VGs) are promising active materials for electric double layer capacitors (EDLCs) due to their unique morphological and structural features. This study, for the first time, reports the molecular dynamics (MD) simulations on aqueous NaCl electrolytes confined within VG c...

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Autores principales: Bo, Zheng, Yang, Huachao, Zhang, Shuo, Yang, Jinyuan, Yan, Jianhua, Cen, Kefa
Formato: Online Artículo Texto
Lenguaje:English
Publicado: Nature Publishing Group 2015
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4589769/
https://www.ncbi.nlm.nih.gov/pubmed/26424365
http://dx.doi.org/10.1038/srep14652
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author Bo, Zheng
Yang, Huachao
Zhang, Shuo
Yang, Jinyuan
Yan, Jianhua
Cen, Kefa
author_facet Bo, Zheng
Yang, Huachao
Zhang, Shuo
Yang, Jinyuan
Yan, Jianhua
Cen, Kefa
author_sort Bo, Zheng
collection PubMed
description Vertically-oriented graphenes (VGs) are promising active materials for electric double layer capacitors (EDLCs) due to their unique morphological and structural features. This study, for the first time, reports the molecular dynamics (MD) simulations on aqueous NaCl electrolytes confined within VG channels with different surface charge densities and channel widths. Simulation results show that the accessibility of ions and the structure of EDLCs are determined by the ion type/size, surface charging, and VG channel width. For relatively narrow VG channels with the same width, the threshold charge density (to compensate the energy penalty for shedding hydration shell) and the dehydration rate of Cl(−) ions are larger than those of Na(+) ions. To achieve the highest ion concentration coefficient, the effective VG channel width should be between the crystal and hydration diameters of the ions. The results are further quantified and elucidated by calculating the electrolyte density profiles. The molecular insights obtained in the current work are useful in guiding the design and fabrication of VGs for advancing their EDLC applications.
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spelling pubmed-45897692015-10-13 Molecular Insights into Aqueous NaCl Electrolytes Confined within Vertically-oriented Graphenes Bo, Zheng Yang, Huachao Zhang, Shuo Yang, Jinyuan Yan, Jianhua Cen, Kefa Sci Rep Article Vertically-oriented graphenes (VGs) are promising active materials for electric double layer capacitors (EDLCs) due to their unique morphological and structural features. This study, for the first time, reports the molecular dynamics (MD) simulations on aqueous NaCl electrolytes confined within VG channels with different surface charge densities and channel widths. Simulation results show that the accessibility of ions and the structure of EDLCs are determined by the ion type/size, surface charging, and VG channel width. For relatively narrow VG channels with the same width, the threshold charge density (to compensate the energy penalty for shedding hydration shell) and the dehydration rate of Cl(−) ions are larger than those of Na(+) ions. To achieve the highest ion concentration coefficient, the effective VG channel width should be between the crystal and hydration diameters of the ions. The results are further quantified and elucidated by calculating the electrolyte density profiles. The molecular insights obtained in the current work are useful in guiding the design and fabrication of VGs for advancing their EDLC applications. Nature Publishing Group 2015-10-01 /pmc/articles/PMC4589769/ /pubmed/26424365 http://dx.doi.org/10.1038/srep14652 Text en Copyright © 2015, Macmillan Publishers Limited http://creativecommons.org/licenses/by/4.0/ This work is licensed under a Creative Commons Attribution 4.0 International License. The images or other third party material in this article are included in the article’s Creative Commons license, unless indicated otherwise in the credit line; if the material is not included under the Creative Commons license, users will need to obtain permission from the license holder to reproduce the material. To view a copy of this license, visit http://creativecommons.org/licenses/by/4.0/
spellingShingle Article
Bo, Zheng
Yang, Huachao
Zhang, Shuo
Yang, Jinyuan
Yan, Jianhua
Cen, Kefa
Molecular Insights into Aqueous NaCl Electrolytes Confined within Vertically-oriented Graphenes
title Molecular Insights into Aqueous NaCl Electrolytes Confined within Vertically-oriented Graphenes
title_full Molecular Insights into Aqueous NaCl Electrolytes Confined within Vertically-oriented Graphenes
title_fullStr Molecular Insights into Aqueous NaCl Electrolytes Confined within Vertically-oriented Graphenes
title_full_unstemmed Molecular Insights into Aqueous NaCl Electrolytes Confined within Vertically-oriented Graphenes
title_short Molecular Insights into Aqueous NaCl Electrolytes Confined within Vertically-oriented Graphenes
title_sort molecular insights into aqueous nacl electrolytes confined within vertically-oriented graphenes
topic Article
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4589769/
https://www.ncbi.nlm.nih.gov/pubmed/26424365
http://dx.doi.org/10.1038/srep14652
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