Electrical properties of lithium bromide poly ethylene oxide / poly vinyl pyrrolidone polymer blend elctrolyte

Highlights: • PEO/PVP based solid polymer electrolytes (SPEs) was prepared with lithium bromide by solution casting technique. • X-ray diffraction studies confirmed the amorphous nature of polymer blend with the inclusion of LiBr. • FT-IR study confirmed the functional groups and the complex formation between the bonding of polymers. • The ionic movement enhances the dielectric loss and dielectric permittivity. • The conductivity relaxation process and the ion hopping mechanism have been explained by using the Electric modulus analysis. -- Abstract: The development of Lithium batteries has gained more attention nowadays. polyethylene oxide (PEO)/Polyvinyl pyrrolidone (PVP) based Solid polymer electrolytes (SPEs) was prepared with lithium bromide by solution casting technique. From the X-ray diffraction studies, the amorphous nature of the polymer blend with the inclusion of LiBr had been studied. FT-IR study was used to find the presence of functional groups and the complex formation between the bonding of polymers. The maximum ionic conductivity was found to be 1.59 × 10⁻⁶ S/cm for PEO (30 wt %)/PVP (70 wt %)/Lithium bromide (4 wt %) at 303 K within the frequency range of 42 Hz - 1 MHz. The dielectric response of the SPE systems was studied at the temperature range of 303–363 K. An important factor of ion conduction is the relaxation behavior of polymer chains which was clarified by the dielectric properties of the SPE systems. Further, the capability of the polymer to dissolve salt was determined by the dielectric constant (ε). At lower frequencies, the higher dielectric permittivity was attained due to deposit of ionic charges. The ionic movement enhances the dielectric loss and dielectric permittivity. The conductivity relaxation process and the ion hopping mechanism have been explained by using the Electric modulus analysis.