Redox-active electrolyte for carbon nanotube-based electric double layer capacitors

[EN] The specific capacitance of the MWCNTs was improved by the addition of an electrochemically active compound (indigo carmine) to an electrolyte generally used in electric double layer capacitors. The pseudocapacitive contribution of the IC trebled the specific capacitance values of the MWCNTs at...

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Detalles Bibliográficos
Autores: Roldán Luna, Silvia, González Arias, Zoraida, Blanco Rodríguez, Clara, Granda Ferreira, Marcos, Menéndez López, Rosa María, Santamaría Ramírez, Ricardo
Tipo de recurso: artículo
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:10261/88978
Acceso en línea:http://hdl.handle.net/10261/88978
Access Level:acceso abierto
Palabra clave:Nanotubes
Cyclic voltammetry
Indigo carmine
Supercapacitor
Pseudocapacitance
Descripción
Sumario:[EN] The specific capacitance of the MWCNTs was improved by the addition of an electrochemically active compound (indigo carmine) to an electrolyte generally used in electric double layer capacitors. The pseudocapacitive contribution of the IC trebled the specific capacitance values of the MWCNTs at low current densities (from 17 Fg−1 to 50 Fg−1). The good resistance obtained for the MWCNT-based capacitor was not modified with the use of this novel redox-active electrolyte. A reversible process associated to the redox reaction of IC was found to be responsible for the capacitance increase observed. Therefore, a combined effect of double layer formation and pseudocapacitive phenomena is presented. Long-term cycling experiments performed showed good stability with a reduction of the initial capacitance values of 30% after 10,000 galvanostatic cycles at 360 mAg−1. The efficiency of the cell was close to 100% throughout the experiment.