In:
ECS Meeting Abstracts, The Electrochemical Society, Vol. MA2019-04, No. 10 ( 2019-06-30), p. 0477-0477
Abstract:
Electrolyte optimization plays a key role in deciding energy density (ED) and power density (PD) of supercapacitors. Increasing cell voltage is an effective way to improve ED and PD. Therefore, an electrolyte with a large potential window is highly desired. Ionic liquid (IL) electrolytes, characterized by wide potential windows, excellent thermal stability, intrinsic ionic conductivity, non-volatility, non-flammability, and low environmental concerns, are potential electrolytes and are used for micropore-and mesopore-rich activated carbon (AC micro and AC meso ) supercapacitors. IL electrolytes consisting of various cations of EMI + ( 1 -ethyl- 3 -methyl imidazolium), PMP + ( N -propyl- N -methyl pyrrolidinium), and BMP + ( N -butyl- N -methyl pyrrolidinium) and various anions of TFSI – (bis(trifluoromethyl sulfonyl) imide), BF 4 – (tetrafluoroborate), and FSI – (bis(fluorosulfonyl)imide) are explored. The electrolyte viscosity and conductivity and ion transport properties at the AC micro and AC meso electrodes are studied. Also, the capacitance, cycling stability, and rate capability of the AC micro and AC meso electrodes are systematically investigated, and post-mortem material analyses are conducted. This study shows the influence of IL composition on charge–discharge capacitances of the AC micro electrodes is more pronounced than that for the AC meso electrodes. The FSI-based IL electrolytes, whose electrochemical properties are dependent on cation, are found to be highly promising. Uniting EMI + with FSI – results in low viscosity of electrolyte and high ion transport, optimizing the electrode capacitance and rate capability. Interchanging EMI + with PMP + enhances the cell voltage (to 3.5 V) and maximum ED (to 42 Wh kg −1 ) of the AC micro cell at the cost of cycling stability.
Type of Medium:
Online Resource
ISSN:
2151-2043
DOI:
10.1149/MA2019-04/10/0477
Language:
Unknown
Publisher:
The Electrochemical Society
Publication Date:
2019
detail.hit.zdb_id:
2438749-6
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