INFLUENCE OF THE PEO MACROMONOMERS ON THE IONIC TRANSPORT AND AGING PROCESSES IN HETEROGENEOUS SOLID POLYMER ELECTROLYTES - A FRACTAL APPROACH

Macromonomer-based solid polymers electrolytes are fully investigated by ac impedance measurements in order to have a better insight into the contribution of the macromonomer in the ionic transfer processes, either in the bulk electrolyte or at the electrolyte-electrode interfaces. A physical meaning of some relevant parameters of the impedance spectrum (bulk conductivity, transfer resistance, relaxation times, phase angle) is proposed in the framework of a heterogeneous electrolytic medium. The deviations of the impedance spectra with respect to the theoretical ones are interpreted in terms of an ionic transfer across a fractal interface. Finally, the behaviour of these electrolytes upon aging is examined and the evolution of the electrochemical performances is discussed. © 1990.