Structure, thermal and electrical properties of PVDF-HFP/LiBOB solid polymer electrolyte

Abstract

Abstract Solid polymer electrolyte (SPE), which is composed of poly (vinylidenefluroride-co-hexafluoropropylene) (PVDF-HFP), lithium bis(oxalate) borate (LiBOB) salt and various concentrations of TiO2 as filler, has been prepared by solution casting technique. Structure, thermal and electrical properties of the SPE were examined using XRD and SEM, TG/DSC, and impedance spectroscopy, respectively. XRD analysis reveals amorphous nature of PVDF-HFP / LiBOB and TiO2 composite matrix. SEM photographs of polymer electrolyte membrane indicate good compatibility between polymer, salt, and other contents as well as amorphous phase formation in the fabricate of SPE. We obtained that (SPE) with composition of 70 wt% polymer, 28 wt% LiBOB and 2 wt% TiO2 has highest conductivity. XRD and DSC analysis indicate that the conductivity increases due to high amount of amorphous nature content. We suggest that the amorphous nature content may enhance segmental flexibility of polymeric chains and disordered structure of the electrolyte.