Field of chemistry which studies rates of electrochemical processes
Electrochemical kinetics is the field of electrochemistry that studies the rate of electrochemical processes. This includes the study of how process conditions, such as concentration and electric potential, influence the rate of oxidation and reduction (redox) reactions that occur at the surface of an electrode, as well as an investigation into electrochemical reaction mechanisms. Two accompanying processes are involved in the electrochemical reaction and influence the overall reaction rate:
Contributors to this field include Alexander Frumkin, John Alfred Valentine Butler, Max Volmer, and Julius Tafel.
Butler-Volmer equation.
An elementary charge transfer step can be described by the Butler–Volmer model proposed by John Alfred Valentine Butler and Max Volmer. The reaction rate is given by the Butler-Volmer equation:
 formula_1
In this equation formula_2 is the net current density, formula_3 is the exchange current density, formula_4 is the charge transfer coefficient, formula_5 is the number of electrons transferred in the reaction, formula_6 is the Faraday constant, formula_7 is the molar gas constant, formula_8 is the absolute temperature, formula_9 is the electrode overpotential, formula_10 is the thermodynamic equilibrium reduction potential and formula_11 is the observed value of this potential.
The equation yields a negative current density for a reduction reaction (negative overpotential) and a positive current density for an oxidation reaction (positive overpotential). The sign of the current density has no physical meaning and is defined by an international convention.