In search of an appropriate ionic liquid as electrolyte for macroporous manganese oxide film electrochemistry

Autor(es)

Benedetti, Tania M. ^[1] ; Goncales, Vinicius R. ^[1] ; Cordoba de Torresi, Susana I. ^[1] ; Torresi, Roberto M. ^[1]

Afiliação do(s) autor(es)

^[1] Univ Sao Paulo, Inst Quim, BR-05513970 Sao Paulo - Brazil

• Tipo de documento: Artigo Científico
• Fonte: Journal of Power Sources; v. 239, p. 1-8, OCT 1 2013.
• Citações Web of Science: 9

Resumo

Macroporous manganese oxide films were produced via template-assisted electrodeposition methodology employing polystyrene spheres with different diameters as template, thereby producing films with different pore sizes. The obtained films were true casts of the template(s) employed, as evidenced by Field Emission Scanning Electron Microscopy. The influence of pore size on capacitive behavior was assessed by cyclic voltammetry experiments in conventional propylene carbonate/LiClO4. Besides the influence of pore size, four different ionic liquids (ILs) were studied as electrolytes, showing that the physico chemical nature of IL strongly affects the capacitive behavior of macroporous manganese oxide films, particularly in terms of stability throughout successive charge/discharge cycles. Optimal performance was obtained using 1-butyl-2,3-dimethylimidazolium bis(trifluoromethanesulfonyl)imide ({[}BMMI]{[}Tf2N]), in which a constant increase in capacitance was observed for the first 700 charge/discharge cycles. This capacitance remained constant, at least until the 1,000 cycle, and was higher than the capacitance achieved using conventional organic solvents. Moreover, the electrochemical window obtained using {[}BMMI]{[}Tf2N] was widened (from 0.9 V to 1.5 V), corresponding to a significant gain (up to 75%) in terms of energy density. Thus, the development of electrochemical capacitors may significantly benefit from macroporous manganese oxide film electrochemistry employing ionic liquids as electrolytes. (C) 2013 Elsevier B.V. All rights reserved. (AU)

• Processo FAPESP: 09/53199-3 - Reconhecimento molecular e armazenamento de energia: estudos fundamentais do efeito de geometria, tamanho e síntese na otimização das propriedades químicas de materiais eletroativos
• Beneficiário: Roberto Manuel Torresi
• Linha de fomento: Auxílio à Pesquisa - Temático
• Processo FAPESP: 12/02117-0 - Uso de poli(líquidos iônicos) em dispositivos eletroquímicos: produção de polieletrólitos para dispositivos de armazenamento e conversão de energia e estabilização de grafeno e Poli(3,4-etilenodioxitiofeno) (PEDOT) para fabricação de filmes eletroativos
• Beneficiário: Tania Machado Benedetti
• Linha de fomento: Bolsas no Brasil - Pós-Doutorado
• Processo FAPESP: 11/15159-0 - Biossensores de terceira geração baseados na interação entre óxido de grafeno reduzido, líquidos iônicos e enzimas oxidases
• Beneficiário: Vinicius Romero Gonçales
• Linha de fomento: Bolsas no Brasil - Pós-Doutorado
• Processo FAPESP: 08/57805-2 - Instituto de Bioanalítica
• Beneficiário: Lauro Tatsuo Kubota
• Linha de fomento: Auxílio à Pesquisa - Temático