New Insight into Ion Dynamics in Nanoporous Carbon Materials: an Application of the Step Potential Electrochemical Spectroscopy (SPECS) Technique and Electrochemical Dilatometry

Abstract This paper reports on the charging mechanism of an activated carbon electrode in a symmetric electrochemical capacitor operating in an ionic liquid electrolyte (EMIm+TFSI−). With the application of step potential electrochemical spectroscopy (SPECS) and electrochemical dilatometry, it is determined that the electrical double-layer formation mechanism strongly depends on the porous structure of the electrode material. Furthermore, SPECS calculations allow us to separate and quantify the charge component responsible for the ionic movement.