Abstract <p>A new composite material based on poly(3,4-ethylenedioxythiophene) polystyrenesulfonate (PEDOT:PSS) and a network of oriented nickel fibers (NiSFs) distributed throughout the polymer matrix is considered as a possible electrode in devices of alternative energetics. The relationship between the electrochemical and electrooptical characteristics of GC/PEDOT:PSS and GC/NiSFs/PEDOT:PSS electrodes is investigated using several electrochemical methods (cyclic voltammetry, electrochemical impedance spectroscopy). By measuring cyclic voltammograms with different potential scanning rates, the mechanism of electrochemical reactions in systems GC/PEDOT:PSS and GC/NiSFs/PEDOT:PSS is studied, and their limiting stages are determined. Based on the redox potentials, the band gap is calculated for these electrodes. F, or GC/PEDOT:PSS the band gap <i>E</i>_g is 1.34 eV. The incorporation of a network of oriented nickel fibers into the PEDOT:PSS matrix only insignificantly narrows the band gap in the system GC/NiSFs/PEDOT:PS to 1.31 eV, which confirms that the optical properties of these materials remain almost unchanged. The GC/PEDOT:PSS and GC/NiSFs/PEDOT:PSS electrodes are studied by impedance spectroscopy. The incorporation of the network of nickel fibers into the polymer film is shown to slow down the charge transfer in the GC/NiSFs/PEDOT:PSS system, as follows from the increase in the charge-transfer resistance <i>R</i>_et to 171 Ω as compared with 131 Ω for unmodified GC/PEDOT:PSS. The analysis of these data makes it possible to conclude that the composite materials based on PEDOT:PSS and a network of oriented nickel fibers can be used in electrooptical devices and power generating systems.</p>