Preparation and characterisation of electrolyte filled solid poly (vinylidene difluoride-co-hexafluoropropylene) polymer TiO2 membranes for battery application

Abstract

ABSTRACT As a prospective electrolyte for potassium-ion batteries, porous polymer electrolytic membranes were prepared based on poly (vinylidene difluoride-co-hexafluoropropylene) (PVDF-co-HFP) by a solution cast method. The casting solution, effects of the solvent, non-solvent and addition of nanoscale TiO2 particles were investigated in this study. The membranes were characterized by scanning electron microscopy (SEM) results in the surface morphology and porous nature of the fabricated membrane. X-ray diffraction (XRD) analysis gives the crystalline phase of the TiO2 doped membrane. The FTIR confirms the different functional groups present in PVDF-co-HFP films. Electrochemical stability of the prepared PVDF-co-HFP-TiO2 was performed by thermogravimetric analysis (TGA). The charge and discharge tests were conducted using the cyclic voltammetric analysis in this study. The addition of TiO2 particles to the polymer electrolyte was found to reduce the porousness of the PVDF-co-HFP membrane and to enhance the electrolyte uptake, ion conductivity and electrolyte/electrode interfacial stability of the membrane.