Structural, Morphological, FTIR, Conductivity, and Dielectric Properties of NaBF ₄ ‐Doped PVDF‐HFP/PVC Blend Polymer Electrolytes

ABSTRACT

In the present work, a solid polymer electrolyte system of different compositions of PVDF‐HFP/PVC/NaBF ₄ was prepared by solution casting method. NaBF ₄ was incorporated as the sodium salt for Na ⁺ ionic source for conduction. The prepared samples were examined using x‐ray diffraction, scanning electron microscopy, Fourier transform infrared spectroscopy, and impedance spectroscopy. The XRD spectra were deconvoluted and results showed reduced crystallinity upon addition of salt to PVDF‐HFP/ PVC blend polymer. The SEM micrographs showed a homogeneous and well‐blended surface, indicating strong polymer–salt interaction. The FTIR studies evidenced dramatic changes in various band positions due to well cross‐linking between PVDF‐HFP, PVC, and NaBF ₄ . This FTIR spectrum confirmed the formation of complexes between Na ⁺ ions and the polymer PVDF‐HFP and PVC blend host. Impedance spectroscopy showed that the optimized electrolyte achieved ionic conductivity was 3.9 × 10 ⁻⁵ S·cm ⁻¹ at room temperature and also investigated the dielectric behavior of the prepared samples throughout a broad frequency range. We analyzed the dielectric constant ( ε ′), dielectric loss ( ε ″), and loss tangent (tan δ ) to better understand the polarization and relaxation processes of the polymer electrolyte system.