The effect of the electrolyte concentration in the solution on the voltammetric response of insertion electrodes

A solid-state redox reaction involving an insertion of ions is analyzed with respect to the influence of the concentration of inserting ions in the solution phase. The voltammetric response is independent of the mass transfer in the solution provided that z = (D-SS/D-aq)(1/2) rho/[C+]* is smaller than 0.1 (D-SS: diffusion coefficient of the cation C+ in the crystal; D-aq: diffusion coefficient of the cation C+ in the solution; rho: density of the solid compound; [C+]*: concentration of cations in the bulk of the solution). In real cases this condition will be satisfied at solution concentrations above 1 mol/l.