Impedance spectroscopy has been used for characterization of the interface between an ideally polarizable electrode and poly(ethylene oxide) electrolytes containing lithium salts. The solvent contribution to the inner layer capacitance, C-s, for CH3O(CH2CH2O)(n)CH3 for (n = 4, 8, 10) and oxymethylene-linked poly(oxyethylene), PMEO was evaluated by subtracting the contribution of the metal (C-m) from the inner layer capacitance. The position of the maximum in the bell-shaped curves C-s(sigma) depends on the molecular mass of the solvent. The influence of the external electric field on the condition of the solvent molecules at the inner layer has been characterized by a dipolar capacitance as a function of effective charge density, C-dip(sigma*) for PEO(n = 4, 8, 10) and solid PMEO. Polyethers with shorter chain have been found to be more sensitive to the external electric field for a negative electrode charge, the slopes of the C-dip(sigma*) curves are changing in sequence: PEO(n = 4)>PEO(n = 8, n = 10)>PMEO. (c) 2005 Elsevier B.V. All rights reserved.