摘要
In this work we have studied the effect of 1,2-dimethoxyethane(1,2-DME) addition(from 0 to 90 vol%)on the electrochemical behaviour of 1-ethyl-3-methylimidazolium bis(trifluoromethylsulphonyl)imide(EMIm TFSI) as an electrolyte for supercapacitors,using cyclic voltammetry,electrochemical impedance spectroscopy and constant power methods.Also,the ionic conductivity and viscosity of EMIm TFSI and1,2-DME have been measured and discussed.The conductivity of the EMIm TFSI could be increased from 5.67 m S/cm up to 24.21 m S/cm by mixing EMIm TFSI with 1,2-DME.The stored power values for supercapacitors increased from 13 k W/kg to 20.5 k W/kg(correspond to 2 s application line),when the concentration of 1,2-DME increased up to 40 vol%.The supercapacitors based on the 40 vol% of 1,2-DME deliver the higher power density at the constant energy density,showing an excellent characteristics applicable in high rate supercapacitor devices.Nearly ideal capacitive behaviour has been established at potential scan rates v ≤ 10 m V/s and cell potential E ≤ 2.7 V.
基金
the Estonian Center of Excellence in Science project 3.2.0101.11-0030
Estonian Energy Technology Program Project 3.2.0501.10-0015
Material Technology Program Project 3.2.1101.12-0019
Project of European Structure Funds 3.2.0601.11-0001
Estonian Target Research Project IUT20–13,and Projects 3.2.0302.10-0169,3.2.0302.10-0165
