Composite material combining electroactive polymer poly(3,4-ethylenedioxythiophene) (pEDOT) and inorganic redox particles of iron(II) hexacyanocobaltate(III) (FehcCo) was tested in contact with aqueous (KCl) and non-aqueous (LiClO4 in an ethylene carbonate:propylene carbonate solution) electrolytes. The pEDOT/FehcCo electrode layers were examined using electrochemical impedance spectroscopy, cyclic voltammetry and chronopotentiometry in the potential range of polymer activity and Faradaic activity of inorganic Fe-3[Co(CN)(6)](2) redox network. The material pEDOT/FehcCo shows good stability and high electrical capacity (similar to 70 F cm(-3) in a LiClO4 non-aqueous electrolyte). The electrode layers of pEDOT/FehcCo are porous and exhibit good adhesion to the electrode surface. (C) 2010 Elsevier B.V. All rights reserved.