Correlation between Capacitance and Porosity in Microporous Carbon Monoliths

Autor:	A. Garcia-Gomez, Teresa A. Centeno, J. M. Rojo, Joaquín Ibáñez, Violeta Barranco, Gelines Moreno-Fernandez
Rok vydání:	2014
Předmět:	Supercapacitor Materials science Nanotechnology Microporous material Electrolyte Capacitance Pseudocapacitance Surfaces Coatings and Films Electronic Optical and Magnetic Materials Ion General Energy Chemical engineering Specific surface area Physical and Theoretical Chemistry Porosity
Zdroj:	Digital.CSIC. Repositorio Institucional del CSIC instname
ISSN:	1932-7455 1932-7447
Popis:	Specific capacitance of carbons in aqueous KOH electrolyte seems to have two contributions, a double-layer capacitance and a pseudocapacitance. Moreover, the specific capacitance increases as the specific surface area does. Here, we report that the pseudocapacitance is associated with the K+ ion and the double-layer capacitance with both K+ and OH- ions. The former ion dominates the capacitance of a real two-electrode supercapacitor. Two microporous carbon monoliths with surface areas similar for micropores below 0.63 nm but different for larger micropores are chosen. There is a correlation between the double-layer capacitance due to those ions and the surface areas due to micropores with sizes above a certain value. It provides information on the size of those ions as they are electroadsorbed at the double layer. The dielectric permittivity associated with the K+ and OH - ion is discussed in relation to the confinement of these electroadsorbed ions in the micropores. © 2014 American Chemical Society. Financial support through the projects MAT2011-25198 and MP 1004 is gratefully acknowledged. V.B. thanks MINECO for R&C contract.
Databáze:	OpenAIRE
Externí odkaz:	https://explore.openaire.eu/search/publication?articleId=doi_dedup___::13ed9cbb94513a49720db3961e47d7ea https://doi.org/10.1021/jp411076a Zobrazit plný text záznamu