Design of a novel redox-active gel polymer electrolyte with a dual-role ionic liquid for flexible supercapacitors. (1st April 2018)

• Record Type: Journal Article
• Authors: Tu, Qiu-Mei; Fan, Le-Qing; Pan, Fei; Huang, Jian-Ling; Gu, Yun; Lin, Jian-Ming; Huang, Miao-Liang; Huang, Yun-Fang; Wu, Ji-Huai
• Is Part Of: Electrochimica acta. Volume 268(2018)
• Page Start: 562
• Page End: 568
• Publication Date: 2018-04-01
• Subjects: Flexible supercapacitor -- Gel polymer electrolyte -- Redox additive -- Ionic liquid -- Pseudocapacitance; Electrochemistry -- Periodicals; Electrochemistry, Industrial -- Periodicals; 541.37
• DOI: 10.1016/j.electacta.2018.02.008
• Languages: English
• ISSNs: 0013-4686

Abstract

Abstract: By choosing an ionic liquid 1-butyl-3-methylimidazolium iodide (BMIMI) as plasticizer and redox additive, along with a neutral Li2 SO4 aqueous solution to achieve wide operating voltage, a redox-active poly(vinyl alcohol) (PVA)-Li2 SO 4 -BMIMI gel polymer electrolyte(GPE) was prepared and used for the assemble of an activated carbon-based flexible supercapacitor. The electrochemical performances of the flexible supercapacitor with an optimized PVA-Li2 SO 4 -BMIMI GPE were evaluated by cyclic voltammetry, galvanostatic charge-discharge and electrochemical impedance spectroscopy techniques. The mechanical performance of the flexible supercapacitor under different bending angles was also discussed. The obtained PVA-Li2 SO 4 -BMIMI GPE exhibits the rarely found elongation at break of up to about 1200%. The flexible supercapacitor can reach a high energy density of 29.3 Wh kg −1, which is attributed to the wide voltage (1.5 V) resulted from the strong solvation of Li + cations and SO4 2− anions, and the pseudocapacitance contributed by Faradaic reactions of the I-based ions in the GPE. Moreover, the flexible supercapacitor shows good cyclic durability and superior mechanical performance. For comparison, the PVA-Li2 SO 4 - BMIMCl GPE was also synthesized and then its performance was studied. Graphical abstract: Highlights: A redox-active gel polymer electrolyte was prepared. Ionic liquid BMIMI acts as plasticizer and redox additive. Gel polymer electrolyte exhibits greatly high elongation at break. Flexible supercapacitor shows high energy density.