Comparing Triflate and Hexafluorophosphate Anions of Ionic Liquids in Polymer Electrolytes for Supercapacitor Applications

Autor: Chiam-Wen Liew, S. Ramesh
Jazyk: angličtina
Rok vydání: 2014
Předmět:
Zdroj: Materials, Vol 7, Iss 5, Pp 4019-4033 (2014)
Druh dokumentu: article
ISSN: 1996-1944
DOI: 10.3390/ma7054019
Popis: Two different ionic liquid-based biopolymer electrolyte systems were prepared using a solution casting technique. Corn starch and lithium hexafluorophosphate (LiPF6) were employed as polymer and salt, respectively. Additionally, two different counteranions of ionic liquids, viz. 1-butyl-3-methylimidazolium hexafluorophosphate (BmImPF6) and 1-butyl-3-methylimidazolium trifluoromethanesulfonate (also known as 1-butyl-3-methylimidazolium triflate) (BmImTf) were used and studied in this present work. The maximum ionic conductivities of (1.47 ± 0.02) × 10−4 and (3.21 ± 0.01) × 10−4 S∙cm−1 were achieved with adulteration of 50 wt% of BmImPF6 and 80 wt% of BmImTf, respectively at ambient temperature. Activated carbon-based electrodes were prepared and used in supercapacitor fabrication. Supercapacitors were then assembled using the most conducting polymer electrolyte from each system. The electrochemical properties of the supercapacitors were then analyzed. The supercapacitor containing the triflate-based biopolymer electrolyte depicted a higher specific capacitance with a wider electrochemical stability window compared to that of the hexafluorophosphate system.
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