Improved ionic conductivity, potential window and dielectric strength in intercalated polymer nanocomposites

Abstract

A nanocomposite solid polymer electrolyte has been synthesized using polyethylene oxide (PEO), sodium hexafluorophosphate (NaPF6), and organomodified montmorillonite (DMMT) nano-clay, with an aim to improve the ionic conductivity, voltage stability window, transference number and dielectric properties. The DMMT intercalated PNCs exhibits an ionic conductivity of three order (∼10-5 S cm-1) higher as compared to the pure polymer (∼10-8 S cm-1). The DMMT based PNCs have ion transference number close to unity (0.99) and wide voltage stability window (∼5V). The dielectric constant and dc conductivity increases with nanoclay addition. The relaxation peak in loss tangent plot shift toward high frequency on nanoclay addition and indicates the decrease of relaxation time. The evaluated relaxation time τϵ′, τtan δ, τh, τm are in good correlation with each other and exhibits minima for the nanoclay based PNCs which infers the faster segmental motion of polymer chain and supports the enhanced ionic conductivity. © 2019 Author(s).