Long-term cycling of carbon-based supercapacitors in aqueous media

[EN] The behaviour of mesophase-derived electrodes on long-duration cycling conditions was studied in 1 M sulfuric acid and 6 M potassium hydroxide. Variation in the specific capacitance values with the number of cycles shows a good cycling life performance in acidic media but very poor in an alkali...

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Detalhes bibliográficos
Autores: Ruiz Ruiz, Vanesa, Santamaría Ramírez, Ricardo, Granda Ferreira, Marcos, Blanco Rodríguez, Clara
Formato: artículo
Fecha de publicación:2009
País:España
Recursos:Consejo Superior de Investigaciones Científicas (CSIC)
Repositorio:DIGITAL.CSIC. Repositorio Institucional del CSIC
OAI Identifier:oai:digital.csic.es:10261/88775
Acesso em linha:http://hdl.handle.net/10261/88775
Access Level:acceso abierto
Palavra-chave:Activated carbon
Electrochemical capacitor
Double layer
Pseudocapacitance
Long-term cycling
Descrição
Resumo:[EN] The behaviour of mesophase-derived electrodes on long-duration cycling conditions was studied in 1 M sulfuric acid and 6 M potassium hydroxide. Variation in the specific capacitance values with the number of cycles shows a good cycling life performance in acidic media but very poor in an alkaline electrolyte. The total loss of capacitance after 7000 cycles in acidic media is 8% at 0.6 V and 16% at 1 V, whereas in the basic electrolyte the reduction in the capacitance values is 72%, even at a very small operating voltage (0.6 V). This behaviour was associated to the strong oxidation of the positive electrode caused by the progressive shift of the working potential towards very positive potential values during cycling.