Logistic Approximation to Ion-Intercalation Electrochemistry: Application to Potassium–Copper(II) Hexacyanoferrate in DMSO Electrolytes

Abstract

Ion-intercalation electrochemistry under quasi-equilibrium conditions is described in terms of a logistic approximation. The theoretical model assumes that the differential capacitance can be expressed as a logistic relationship between the transferred charge and the applied potential. This semiempirical model provides analytical solutions for the constitutive equations, including a simplified account of uncompensated resistive and capacitive effects in the cell. The model is applied to describe the Fe-and Cucentered voltammetry of a synthetic potassium−copper hexacyanoferrate in contact with Li + -, Na + -, and K + -containing DMSO electrolyte solutions with satisfactory results.