TAFEL EQUATION

"An early (1905) empirical relation between the overpotential of the electrode and the current density passing through the electrode: ? = a + b*logi , where ? is the overpotential , I - the current density ; ""a"" and ""b"" are characteristic constants of the electrode system. A plot of electrode potential versus the logarithm of current density is called the ""Tafel plot"" and the resulting straight line the ""Tafel line."" ""b"" is the ""Tafel slope"" that provides information about the mechanism of the reaction, and ""a"" provides information about the rate constant (and the exchange current density) of the reaction. "