electrodesolution

Electrode dissolution is the loss of electrode material into the electrolyte during electrochemical operation. It occurs when an electrode is oxidized at the anode or when a sacrificial electrode releases ions to the solution. The term electrode dissolution is sometimes used interchangeably with anodic dissolution. It is a key consideration in corrosion, electroplating, and electrochemical machining.

The dissolution rate depends on electrode potential and current, electrolyte composition and pH, temperature, and surface properties. Passive films can slow dissolution, while active, finely divided, or alloyed materials may dissolve rapidly. Complexing ligands, chlorides, and galvanic coupling can either promote or direct dissolution. Mass transport to the electrode interface and surface roughness also influence dissolution rates.

In industry, dissolution can be undesirable, causing material loss and failure, but it can be purposeful, for example in electrodeposition, sacrificial protection, and electropolishing. In energy storage, dissolution of active materials from electrodes can contribute to capacity fade and impedance growth during cycling.

Dissolution rates are commonly estimated from Faraday’s law, relating material loss to the total charge passed and the stoichiometry of the dissolution reaction. Control strategies include selecting more resistant materials, applying protective coatings, operating at potentials that minimize oxidation, using inhibitors, and optimizing electrolyte composition and temperature. Analytical methods such as mass loss measurements, ion analysis, and electrochemical techniques (cyclic voltammetry, impedance spectroscopy) are used to study and monitor electrode dissolution.