Surface-related capacitance of microporous carbons in aqueous and organic electrolytes

This paper examines the surface-related capacitance C/S of carbons with average micropore widths between 0.73 and 1.80 nm, using 1–2 M H2SO4, 6 M KOH and 1 M (C2H5)4NBF4 in acetonitrile as electrolytes. Following corrections for pseudocapacitance effects for the aqueous electrolytes and the use of a...

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Detalles Bibliográficos
Autores: Álvarez Centeno, Teresa, Stoeckli, Fritz
Tipo de recurso: artículo
Estado:Versión aceptada para publicación
Fecha de publicación:2011
País:España
Institución:Consejo Superior de Investigaciones Científicas (CSIC)
Repositorio:DIGITAL.CSIC. Repositorio Institucional del CSIC
OAI Identifier:oai:digital.csic.es:10261/100230
Acceso en línea:http://hdl.handle.net/10261/100230
Access Level:acceso abierto
Palabra clave:Electrochemical capacitor
Carbon
Microporosity
Surface functionalities
Dielectric constant
Descripción
Sumario:This paper examines the surface-related capacitance C/S of carbons with average micropore widths between 0.73 and 1.80 nm, using 1–2 M H2SO4, 6 M KOH and 1 M (C2H5)4NBF4 in acetonitrile as electrolytes. Following corrections for pseudocapacitance effects for the aqueous electrolytes and the use of an average surface area suggested by independent techniques, different from the BET area, it appears that C/S is practically independent of the micropore width. The analysis of the data with the help of recent models suggests that the dielectric constants ɛr of the different electrolytes may decrease with the pore size. It is surprising that the coexistence of two sets of values for the surface area of microporous carbons and its consequence on C/S have not received more attention in the past.