Nonlinear conductive spectra of ion-conducting polymers

An ion-conducting polymer, tetraethylene oxide-organosiloxane (TEOS) copolymer, was synthesized and the linear and nonlinear complex conductivities were measured as a function of frequency. Observed spectra were reproduced by taking into account the interfacial and electrode polarizations. The most important findings are the very large dielectric relaxation strength and the very long hopping distance in noncrystalline ion-conducting polymers. The large relaxation strength suggests that the TEOS/Li^- comprises an inhomogeneous system consisting of highly conductive and less conductive regions. It is speculated that such inhomogeneity governs the conduction mechanisms of the ionic conductor and results in a very long hopping distance. A combination of linear and nonlinear DC conductivities leads to a hopping distance of 200 nm.