High energy density and high working voltage of a quasi-solid-state supercapacitor with a redox-active ionic liquid added gel polymer electrolyte
| Autor: | Cheng-Long Geng, Na Liu, Jihuai Wu, Si-Jia Sun, Ze-Yu Song, Chun-Yan Wang, Yong-Lan Wang, Leqing Fan |
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| Rok vydání: | 2019 |
| Předmět: |
Supercapacitor
02 engineering and technology General Chemistry Electrolyte 010402 general chemistry 021001 nanoscience & nanotechnology Electrochemistry 01 natural sciences Catalysis 0104 chemical sciences Dielectric spectroscopy chemistry.chemical_compound chemistry Chemical engineering Ionic liquid Materials Chemistry Ionic conductivity Cyclic voltammetry 0210 nano-technology Quasi-solid |
| Zdroj: | New Journal of Chemistry. 43:18935-18942 |
| ISSN: | 1369-9261 1144-0546 |
| Popis: | To increase the energy density of quasi-solid-state supercapacitors, a redox-active gel polymer electrolyte (GPE) was prepared by evaporating the excess water in a neutral gel that consists of polyvinyl alcohol (PVA), Na2SO4 and the ionic liquid (IL) N-butyl-N-methylpyrrolidinium bromide (Pyr14Br). The influence of IL Pyr14Br on the ionic conductivity of GPE was investigated. The maximum ionic conductivity of PVA–Na2SO4–Pyr14Br GPE can reach 27.1 mS cm−1. The optimized GPE was assembled with two activated carbon electrodes into a quasi-solid-state supercapacitor. The electrochemical performances of this supercapacitor were evaluated by cyclic voltammetry, galvanostatic charge/discharge, electrochemical impedance spectroscopy and self-discharge measurements. The assembled supercapacitor exhibits a high energy density of 33.0 W h kg−1, which is due to the wide working voltage (2.0 V) as a result of the strong solvation of Na+ cations and SO42− anions and the production of an additional pseudocapacitive contribution from the Br−/Br3− redox reaction at the electrolyte/electrode interface. This supercapacitor exhibits outstanding cyclic stability with an 81.0% capacitance retention ratio after 8000 charge/discharge cycles. Moreover, this supercapacitor presents good self-discharge behavior. |
| Databáze: | OpenAIRE |
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