“…The concentration polarization is caused by the mass diffusion, since the applied current added to the electrode produces a concentration gradient near the electrode surface. The concentration polarization in the anode and cathode are [ 18 , 19 , 20 , 31 , 32 , 33 , 34 , 35 , 36 ]: where is the limiting current density, is the number of reactive electrons, is the current density, and is the area of the electrode.…”