Voltage as Electromotive Force

Definition

Voltage in corrosion is the electromotive force, arising from the energy mismatch between the unstable metal lattice and a strong electron sink, that compels electrons to move. It is the driving force of the corrosion cell.

Metals sit at a higher energy state than they prefer while oxygen, with high electronegativity and favorable reduction thermodynamics, acts as a strong electron sink. The difference between these states is the voltage that turns chemistry into electricity once continuous electron and ion paths exist. Voltage increases with strong oxidizers, oxygen gradients, and galvanic couples, and a larger voltage drives a faster corrosion current.

Related concepts

Ohm’s Law in Corrosion · Corrosion Cell · Galvanic Corrosion

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Part of The Blueprint of Water · ⚡ electrochemistry