Electrochemical fundamentals | Electrochemical fundamentals | Double layer

Models of the electric double layer at the interface between a metal and an electrolyte solution are reviewed, starting from the Helmholtz model, which is a fair description at high electrolyte concentrations, and the Gouy–Chapman theory valid at low concentrations. Modern approaches, which allow a more detailed description, are often based on integral equation techniques or on classical density functional theory. Computer simulations, based on classical models or on quantum density functional theory, have shed some light on the structure of the solvent, principally of water, near the metal surface. Recent research focuses on special topics like graphite electrodes, ionic liquids, and combinations of quantum and classical density-functional theory.