Amplified Dielectric Properties of PVDF–HFP/SrTiO₃ Nanocomposites for a Flexible Film Capacitor

Abstract

A simple solution casting technique was used to fabricate perovskite strontium titanate (SrTiO3)-loaded poly(vinylidenefluoride-co-hexafluoropropylene) (PVDF–HFP) nanocomposite films for efficient energy storage applications. Various microscopic and spectroscopic methods were used to study the characteristics of the polymer nanocomposite films, like Fourier transform infrared spectroscopy (FTIR), X-ray diffraction technique (XRD), field emission scanning electron microscopy (FESEM), ultraviolet–visible spectroscopy, thermogravimetric analysis, and mechanical tensile test (stress vs strain). The FTIR, XRD, and FESEM analyses confirmed the incorporation and proper dispersion of SrTiO3 nanoparticles in the PVDF–HFP polymer matrix. An improvement in the optical, thermal, and mechanical behavior of the nanocomposite film was observed compared to the pure polymer. The values of dielectric constant, loss tangent, and AC conductivity of pure PVDF–HFP polymer and PVDF–HFP/SrTiO3 nanocomposites (2, 6, and 10 wt % SrTiO3 loadings) were analyzed in a temperature and frequency span of 30–150 °C and 1–100 kHz, respectively. To better understand the electrical properties of the materials, Nyquist plots were generated, and their related circuit designs were fitted. The 2 wt % SrTiO3 loaded nanocomposite exhibited the highest dielectric enhancement and AC conductivity compared to higher filler-loaded nanocomposites. This exceptional dielectric enhancement at very small filler loading is beneficial for commercialization and economically viable for real-time applications.

Enhanced electroactive β‐phase and dielectric properties in P(VDF‐HFP) composite flexible films through doping with three calcium chloride salts: CaCl2, CaCl2·2H2O, and CaCl2·6H2O

“…Nevertheless, the recorded tensile strength and elongation at break values for the P(VDF‐HFP) film filled with 3 wt% CaCl 2 ·6H 2 O exceeded those of the pure P(VDF‐HFP) film, with respective values of 11.9 MPa and 260%, as reported by Panda and Pasha 60 . Furthermore, the reduction in these values within the composites significantly enhances film flexibility, facilitating easy deformation under applied force.…”

“…Subsequently, the curve transitions from elastic to plastic deformation, reaching a yield point where plastic deformation occurs. The stress value at the fracture point, representing a polymer's ability to withstand a pulling force, defines the tensile strength for the P(VDF‐HFP) copolymer 60,61 . Analyzing Table 2 reveals that the Young's modulus value in the elastic region, derived from Equation (3), decreases with an increase in calcium salt concentrations.…”

Energy Storage Performance of Polymer-Based Dielectric Composites with Two-Dimensional Fillers

“…The most popular high-k and lead-free materials are BaTiO 3 [145], SrTiO 3 [146,147], Ba/SrTiO 3 [137,148], and BiFeO 3 [149]. Wen et al reported BT/PVDF composites using 2D platelets, which were prepared and investigated in this work (Figure 11a-d) [20].…”