Influence of solvent nature on the electrochemical characteristics of nanoporous carbon|1 M (C 2H 5) 3CH 3NBF 4 electrolyte solution interface

Abstract

Electrochemical characteristics of the nanoporous carbon|acetonitrile (AN), γ-butyrolactone (γ-BL) and propylene carbonate (PC) interface with addition of (C 2H 5) 3CH 3NBF 4 electrolyte have been studied by cyclic voltammetry and electrochemical impedance spectroscopy. The region of ideal polarisability, values of series and parallel capacitance, pore resistance and other characteristics dependent on the viscosity of solvents and molar conductivity of electrolyte have been established. Analysis of complex plane plots shows that the nanoporous carbon|1 M (C 2H 5) 3CH 3NBF 4 electrolyte interface can be simulated by an equivalent circuit, in which the two parallel conduction parts in the solid and liquid phases are interconnected by the double layer capacitance in parallel with the complex admittance of hindered reaction of the charge transfer process or of the partial charge transfer process. The values of the characteristic frequency depend on the electrolyte composition and on the electrode potential, i.e., on the viscosity and dipole moment of ions adsorbed at the surface of nanoporous carbon electrode.