Complex electrical impedance and dielectric spectroscopy of Na⁺-conducting PEO/PVP/NaIO₄ solid polymer electrolyte with incorporated nano-sized Graphene Oxide

Being of significant interest as electrolytic materials for mini-mobile energy storage devices, we have studied solid-state polymer-based electrolytic systems – nanocomposites, in particular, NaIO4 salt-complexed poly(ethylene oxide) (PEO)/polyvinyl pyrrolidone (PVP) polymer blends doped with nano-sized Graphene Oxide (GO). The GO monolayer average size and thickness were 5 μm and 2 nm, respectively. In the PEO/PVP polymer blend, the PEO:PVP ratio was 70:30 weight percent (wt.%), the concentration of the salt sodium metaperiodate NaIO4 was 10 wt.%. The nano-sized GO was dispersed with concentration of 0.2; 0.4 and 0.6 wt.%. Thin films (150 μm) of GO/PEO/PVP/NaIO4 Na+ ion-conducting nanocomposites were produced by solution casting technique. They were studied by complex electrical impedance and dielectric spectroscopy in the frequency range 0.1 Hz – 1 MHz of the applied electric field. The room-temperature ion conductivity, the complex dielectric function, dielectric loss and AC conductivity of GO/PEO/PVP/NaIO4 at various concentration of GO were obtained, and the effect from the GO nanofillers was estimated.