Ion conducting nano-composite polymer electrolytes: synthesis and ion transport characterization

Abstract

Synthesis and ion transport characterization of a new K+-ion conducting nano-composite polymer electrolytes (NCPEs): (1−x) [70PEO:30KBr] + x SiO2, where 0 < x < 20 wt%, are reported. The present NCPEs have been cast using a novel hot-press technique in place of the traditional solution cast method. The conventional solid polymer electrolyte (SPE) composition: (70PEO:30KBr), identified as the highest conducting composition at room temperature, has been used as first-phase host matrix and nano-size (~8 nm) particles of SiO2 as second-phase dispersoid. As a consequence of dispersal of SiO2 in SPE host, two orders of conductivity enhancement have been observed in NCPE composition: [95(70PEO:30KBr) + 5SiO2] and this has been referred to as optimum conducting composition (OCC). The polymer-salt/nano-filler SiO2 complexation and thermal properties characterization were done with the help of XRD, FTIR, SEM, DSC and TGA studies. The ion transport behavior in NCPEs have been discussed on the basis of experimental measurements on some basic ionic parameters, viz. conductivity (σ), ionic mobility (μ), mobile ion concentration (n), ionic transference number (tion), etc. The temperature-dependent conductivity studies of NCPE OCC have been done and activation energy (Ea) value was determined using log σ−1/T Arrhenius plot.