PROPERTIES OF POLARIZATION CURVES FOR ELECTROCHEMICAL-CELLS DESCRIBEDBY BUTLER-VOLMER KINETICS AND ARBITRARY VALUES OF THE TRANSFER-COEFFICIENT

Theoretical investigation of potentiostatic electrolysis of a metallic salt in three component electrolyte solution was carried out for a ce ll consisting of two identical parallel electrodes. Analytical and num erical results are given for polarization curves for electrochemical c ells with arbitrary values of transfer coefficient alpha and exchange current density. Theoretical analysis of the electrodiffusion problem, based on an exact solution of the Nernst-Planck equations with bounda ry conditions of Butler-Volmer type, led to a formula for the polariza tion curve that is similar to the Tafel equation but with an effective transfer coefficient alpha(eff) = alpha(1 - alpha). It was shown that , under certain conditions, the polarization curve can have two inflec tion points.