Activation overpotential, also called surface overpotential, is the potential difference above the equilibrium potential required to overcome the activation energy of the cell reaction to produce a specified current.

What is meant by overpotential?

In electrochemistry, overpotential is the potential difference (voltage) between a half-reaction's thermodynamically determined reduction potential and the potential at which the redox event is experimentally observed. ... The term is directly related to a cell's voltage efficiency.

What is overpotential or overvoltage?

Overpotential: The difference in the electrode potential of an electrode between its equilibrium potential and its operating potential when a current is flowing. ... Overvoltage: The difference between the cell voltage (with a current flowing) and the open-circuit voltage (ocv).