Cargando…

Carbons with Regular Pore Geometry Yield Fundamental Insights into Supercapacitor Charge Storage

[Image: see text] We conduct molecular dynamics simulations of electrical double-layer capacitors (EDLCs) using a library of ordered, porous carbon electrode materials called zeolite templated carbons (ZTCs). The well-defined pore shapes of the ZTCs enable us to determine the influence of pore geome...

Descripción completa

Detalles Bibliográficos
Autores principales: Liu, Yifei Michelle, Merlet, Céline, Smit, Berend
Formato: Online Artículo Texto
Lenguaje:English
Publicado: American Chemical Society 2019
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6891853/
https://www.ncbi.nlm.nih.gov/pubmed/31807683
http://dx.doi.org/10.1021/acscentsci.9b00800
_version_ 1783475912285618176
author Liu, Yifei Michelle
Merlet, Céline
Smit, Berend
author_facet Liu, Yifei Michelle
Merlet, Céline
Smit, Berend
author_sort Liu, Yifei Michelle
collection PubMed
description [Image: see text] We conduct molecular dynamics simulations of electrical double-layer capacitors (EDLCs) using a library of ordered, porous carbon electrode materials called zeolite templated carbons (ZTCs). The well-defined pore shapes of the ZTCs enable us to determine the influence of pore geometry on both charging dynamics and charge storage mechanisms in EDLCs, also referred to as supercapacitors. We show that charging dynamics are negatively correlated with the pore-limiting diameter of the electrode material and display signatures of both progressive charging and ion trapping. However, the equilibrium capacitance, unlike charging dynamics, is not strongly correlated to commonly used, purely geometric descriptors such as pore size. Instead, we find a strong correlation of capacitance to the charge compensation per carbon (CCpC), a descriptor we define in this work as the average charge of the electrode atoms within the coordination shell of a counterion. A high CCpC indicates efficient charge storage, as the strong partial charges of the electrode are able to screen counterion charge, enabling higher ion loading and thus more charge storage within the electrode at a fixed applied voltage. We determine that adsorption sites with a high CCpC tend to be found within pockets with a smaller radius of curvature, where the counterions are able to minimize their distance with multiple points on the electrode surface, and therefore induce stronger local partial charges.
format Online
Article
Text
id pubmed-6891853
institution National Center for Biotechnology Information
language English
publishDate 2019
publisher American Chemical Society
record_format MEDLINE/PubMed
spelling pubmed-68918532019-12-05 Carbons with Regular Pore Geometry Yield Fundamental Insights into Supercapacitor Charge Storage Liu, Yifei Michelle Merlet, Céline Smit, Berend ACS Cent Sci [Image: see text] We conduct molecular dynamics simulations of electrical double-layer capacitors (EDLCs) using a library of ordered, porous carbon electrode materials called zeolite templated carbons (ZTCs). The well-defined pore shapes of the ZTCs enable us to determine the influence of pore geometry on both charging dynamics and charge storage mechanisms in EDLCs, also referred to as supercapacitors. We show that charging dynamics are negatively correlated with the pore-limiting diameter of the electrode material and display signatures of both progressive charging and ion trapping. However, the equilibrium capacitance, unlike charging dynamics, is not strongly correlated to commonly used, purely geometric descriptors such as pore size. Instead, we find a strong correlation of capacitance to the charge compensation per carbon (CCpC), a descriptor we define in this work as the average charge of the electrode atoms within the coordination shell of a counterion. A high CCpC indicates efficient charge storage, as the strong partial charges of the electrode are able to screen counterion charge, enabling higher ion loading and thus more charge storage within the electrode at a fixed applied voltage. We determine that adsorption sites with a high CCpC tend to be found within pockets with a smaller radius of curvature, where the counterions are able to minimize their distance with multiple points on the electrode surface, and therefore induce stronger local partial charges. American Chemical Society 2019-11-15 2019-11-27 /pmc/articles/PMC6891853/ /pubmed/31807683 http://dx.doi.org/10.1021/acscentsci.9b00800 Text en Copyright © 2019 American Chemical Society This is an open access article published under an ACS AuthorChoice License (http://pubs.acs.org/page/policy/authorchoice_termsofuse.html) , which permits copying and redistribution of the article or any adaptations for non-commercial purposes.
spellingShingle Liu, Yifei Michelle
Merlet, Céline
Smit, Berend
Carbons with Regular Pore Geometry Yield Fundamental Insights into Supercapacitor Charge Storage
title Carbons with Regular Pore Geometry Yield Fundamental Insights into Supercapacitor Charge Storage
title_full Carbons with Regular Pore Geometry Yield Fundamental Insights into Supercapacitor Charge Storage
title_fullStr Carbons with Regular Pore Geometry Yield Fundamental Insights into Supercapacitor Charge Storage
title_full_unstemmed Carbons with Regular Pore Geometry Yield Fundamental Insights into Supercapacitor Charge Storage
title_short Carbons with Regular Pore Geometry Yield Fundamental Insights into Supercapacitor Charge Storage
title_sort carbons with regular pore geometry yield fundamental insights into supercapacitor charge storage
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6891853/
https://www.ncbi.nlm.nih.gov/pubmed/31807683
http://dx.doi.org/10.1021/acscentsci.9b00800
work_keys_str_mv AT liuyifeimichelle carbonswithregularporegeometryyieldfundamentalinsightsintosupercapacitorchargestorage
AT merletceline carbonswithregularporegeometryyieldfundamentalinsightsintosupercapacitorchargestorage
AT smitberend carbonswithregularporegeometryyieldfundamentalinsightsintosupercapacitorchargestorage