Solvent-Free ILs for EDLCs

FIGURE 2.61 Cyclic voltammograms measured at cell voltage scan rate 1 mV s for ES test cells with various ILs. (Reproduced by permission of The Electrochemical Society from Kurig, H. et al. 2012. Journal of the Electrochemical Society 159 A944-A951.) 

Consequently, the [EMIM][BF4] IL-based EDLC exhibited a highest specific energy density of 67 Wh kg- at a cnrrent density of 1 A g-.  

Apart from [EMIM]+ cation, researchers have explored other imidazolium-based cations such as l-butyl-2,3-dimethylimidazolium bis(trifluoromethylsulfonyl) imide ([BDMIM]), l-butyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide ([BMIM]), and l-dodecyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide ([C12MIM]) [627,628]. For example, Bettini et al. [628] investigated four ILs including [BMIM][NTf2], [Ci2MIM][NTf2], [EMIM][NTf2], and 1-butyl-l-methylpyrrolidinium 

FIGURE 2.65 Capacitance performance of the electrolyte at different electrolytes, (a) CV curves of the CNT electrode in different electrolytes at a scan rate of 200 mV s . (b) Specific capacitance of the CNT electrode in different electrolytes at different scan rates, (c) Energy density of the CNT electrode in different electrolytes, (d) EIS. (Kong, C. Y., W. Z. Qian, C. Zheng, Y. T. Yu, C. J. Cui, and F. Wei. 2013. Raising the performance of a4 V supercapacitor based on an EMIBF4-single walled carbon nanotube nanofluid electrolyte. Chemical Communications 49 10727-10729. Reproduced by permission of The Royal Society of Chemistry.) 

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