Graphene Oxide‐Tailored PVDF‐HFP Nanocomposite Electrolytes: A Study of Structural, Thermal, Ionic Conductivity, and Dielectric Properties

ABSTRACT This study reports on the structural, thermal, ionic conductivity, and dielectric properties of nanocomposite polymer electrolytes (NCPEs) based on PVDF‐HFP matrix, plasticized with succinonitrile (SN), and embedded with LiTFSI salt and graphene oxide (GO) nanofiller. FTIR analysis indicate strong interactions among the electrolyte components that reduce polymer crystallinity, as directly shown by a decrease in melting enthalpy in DSC thermograms. Electrochemical impedance spectroscopy demonstrates a substantial enhancement in room‐temperature ionic conductivity, reaching 4.44 × 10 −4 S cm −1 for a sample containing 0.3 wt.% GO, a four‐fold increase over the plasticized system without GO. The improvement is attributed to GO's oxygenated functional groups facilitating salt dissociation, reducing host crystallinity, and its layered structure providing ion‐conducting pathways. However, increasing GO concentration beyond 0.3 wt.% results in hindering ion transport and deteriorating performance, which is attributed to the filler aggregation. Temperature‐dependent ionic conductivity follows Arrhenius behavior, indicating an ion hopping mechanism, and achieves a high value of 1.6 × 10 − 3 S cm − 1 at 393 K. The NCPEs exhibit a higher total ionic transference number (> 0.9), confirming predominantly ionic conduction. Dielectric and electric modulus analysis reveal significant electrode polarization at low frequencies and a higher dielectric constant in the low frequency region for the optimized electrolyte composition, supporting the conductivity results. Furthermore, the addition of GO also resulted in improved mechanical properties, as evidenced by the tensile testing results.