Electrical Double Layer Capacitors Based on Two 1-Ethyl-3-Methylimidazolium Ionic Liquids with Different Anions

The electrochemical characteristics for the electrical double layer capacitors (EDLCs) based on the microporous carbon cloth (MPCC) electrode and 1-ethyl-3-methyl imidazolium tetrafluoroborate or 1-ethyl-3-methyl imidazolium tetracyanoborate as an electrolyte have been studied using the cyclic voltammetry and impedance spectroscopy methods. The considerable dependence of gravimetric series capacitance, phase angle, power and energy densities on the composition of the anion in room-temperature ionic liquid (RTIL) have been demonstrated. The region of ideal polarisability for both MPCC vertical bar RTIL EDLCs is up to 3.2 V. (C) 2011 The Electrochemical Society. [DOI: 10.1149/1.3596722] All rights reserved.