On a Generalization of the Electroneutrality Condition

V. V. Nikonenko , M. Kh. Urtenov
Российский электрохимический журнал
Abstract / Full Text

The condition of the quasi-uniform distribution of the space-charge density (the QDC condition),which generalizes the electroneutrality condition, is suggested. It is shown that the use of the QDC condition,in conjunction with the system of equations consisting of the Nernst–Planck and Poisson equations, allows oneto find approximately the distribution of concentrations of cations and anions of a binary electrolyte, as well asthe electrical-field strengths both at sublimiting and overlimiting current densities. The concentration distributions obtained coincide with the corresponding “exact” functions found by means of the Poisson equation overthe entire diffusion layer except for a thin, quasi-equilibrium boundary layer with a thickness of the order of theDebye length.