Elements of Electrostatics Involved in Treatment of Double Layers and Ions at Capacitor Electrode Interphases

Abstract

The electrochemistry of double layers, and the ions and solvent molecules constituting them, involves the electrostatic energies and molecular or ionic distributions of these species in high interphasial fields. At charged electrode interphases in double layers, the electric fields can become as high as 10⁷ V cm^-1, and similarly in the solvation shells of ions. The electrostatics of such interphases are concerned with:

• 1. the energies of individual charges and molecular electric dipoles, and of their interactions;

• 2. the motions of individual charges (ions) in fields;

• 3. the configuration of groups of charges on ionized complex molecules (e.g., ionic centers arising at conducting polymers) currently being developed as pseudocapacitors;

• 4. the orientational movement of electric dipoles in homogeneous fields;

• 5. the translational motion of dipoles in inhomogeneous fields;

• 6. the interaction of solvent dipoles with electric fields, and quadrupoles with field gradients; and

• 7. the effective local dielectric coefficient in the double-layer interphase.