Influence of solvent nature on the electrochemical parameters of electrical double layer capacitors

Electrical double layer capacitors based on ideally polarizable nanoporous carbon electrodes in acetonitrile, gamma-butyrolactone and propylene carbonate as the solvents for the 1.0 M (C2H5)(3)CH3NBF4 electrolyte have been tested by cyclic voltammetry and electrochemical impedance methods. The limits of ideal polarizability, low-frequency limiting capacitance and series resistance, time constant, complex power components and other characteristics have been discussed. The applicability limits of the Srinivasan and Weidner model have been tested and the very strong influence of the solvent nature (viscosity and molar conductivity of the solution) on the characteristics of the nanoporous carbon electrode cells has been established. (C) 2003 Elsevier B.V. All rights reserved.