Nanocomposite Solid Polymer Electrolytes with Polymer Blend (PVDF-HFP/Pluronic) as Matrix and GO as Nanofiller: Preparation, Structural Characterization, and Lithium-Ion Conductivity Analysis

Nanocomposite solid polymer electrolytes (NSPEs) with PVDF-HFP/Pluronic as blend polymer matrix, graphene oxide (GO) as nanofiller, and LiClO4 are reported. FTIR spectroscopy reveals the crystal phase transformation of PVDF-HFP from nonpolar & alpha; phase to electroactive & gamma; phase upon salt addition that suggests the ion-dipole interaction between the salt and the matrix. Further, Pluronic not only hinders the PVDF crystallization that increases the amorphous character of the matrix but also interacts with the salt and hence assists in salt dissociation in the blend matrix. The dc conductivity of PVDF-HFP/Pluronic/LiClO4 blend SPE improves with increasing the Pluronic content reaching 0.73 x 10-6 Scm-1 at room temperature with 60 wt.% Pluronic. The dispersion of GO in the same blend SPE leads to a significant jump in room temperature ion conductivity (& AP;1.2 x 10-6 Scm-1) with 0.4% GO. Temperature-dependent ion conductivity of the NSPEs reveals an Arrhenius type thermally activated process. The dc polarization data indicates that the conductivity is predominantly due to ions. Impedance plots exhibit a distorted semicircle at higher frequency and a tilted spike at lower frequency. The spike is an indication of ion diffusion and electrode polarization effect. Further, GO also has enhanced the mechanical properties of the fabricated NSPEs. Nanocomposite solid polymer electrolytes (NSPEs) with blend (PVDF-HFP/Pluronic) polymer matrix and GO as nanofiller are reported. The interaction between the lithium salt and PVDF-HFP induces the crystal phase transformation of PVDF-HFP from nonpolar & alpha; phase to electroactive & gamma; phase. The dc conductivity of the NSPEs improves with increasing Pluronic content and then further enhancement is achieved by dispersing GO as nanofiller. image