WHAT IS THE MEANING OF” Overvoltage in electrochemistry”?
In electrochemistry, overvoltage is synonymous with overpotential. Look up overpotential instead of overvoltage to get details of what it is. Basically, it is a potential that develop because of limited reaction kinetic. It works to reduce the voltage of the electrochemical cell. Think of it like this. For a given redox reaction pair that represents a chemical cell, it has a theoretical voltage determined by thermodynamics. This is typically called the open cell voltage. It’s the maximum voltage that you could harness out of this reaction if you were to make this into a battery. That is all very good and all except for the little detail of reaction kinetics. In reality, you don’t ever get the maximum voltage at open cell. Once current start flowing, limitations on rate of reaction at the cathode and anode develop. Reactions are not infinitely fast. Once you start the reaction, the region near the electrodes are depleted of ion species as they are oxidized or reduced into and out of the
