In the present paper the effect of the salt concentration on the formation and growth of the resistive layers at the polymer electrolyte-lithium electrode interface is analyzed. The studies are performed for poly(ethylene oxide)dimethyl ether (PEODME) doped with LiClO4 electrolytes. It is shown that the rate of growth of the resistivity of interfacial layers depends on the concentration of the added salt and increases as the salt concentration increases. We have related this effect to the decrease in the lithium cation transference number and the increase in the fraction of ionic aggregates occurring with an increase in the salt concentration in polymeric electrolytes. The observed phenomena seem to be important from the viewpoint of application of polymeric electrolytes in lithium or (and) lithium ion batteries. (c) 2006 Elsevier B.V. All rights reserved.