Fabrication and dielectric performance of RGO-PANI reinforced PVDF/BaTiO3 composite for energy harvesting

Abstract

Today’s techno savvy world demands smart devices which are light-weight, flexible, and scalable. Functional polymers and their composites are suitable candidates that can fulfill the requirements in flexible device applications. Polyvinylidene fluoride (PVDF) is one kind of functional polymers possessing a large dielectric strength as well as permanent electrical dipole. To improve the dielectric and ferroelectric performance of the PVDF polymer, it can be hybridized with an inorganic/organic inclusion phase, usually ferroelectric ceramic particles or nano-sized low dimensional carbon. In this work, reduced- graphene oxide (RGO) and RGO-PANI were chosen as the inclusion phase (filler). The present work focuses towards enhancing the dielectric and ferroelectric properties of PVDF-BaTiO3 (P/BT) nanocomposites impregnated with RGO and RGO/PANI(Polyaniline) nanofillers. In-situ polymerization method was adapted to fabricate the RGO/PANI nanocomposite and spin coating method for P/BT composites. X-ray diffractograms and FTIR corroborate the presence of ferroelectric phases in P/BT matrix. Wayne Kerr precision impedance analyzer was used in the frequency frame of 1 Hz to 1 MHz and temperature window from 30 °C to 160 °C to study the dielectric properties. The P-E hysteresis loops were obtained using Radiant Ferroelectric Tester at different voltage cycles. The dielectric constant of P/BT matrix with 0.03% RGO loading exhibited the highest dielectric constant 2 × 105. Remarkable increase in the energy density of composites with filler loading was observed. P/BT with 1 wt% loading of RGO-PANI achieved the maximum value of polarization 3.6 µC/cm2 and discharge energy density 0.76 J/cm3 (under the electric field of 170 kV/cm) with 55% efficiency. This contribution provides a potential route to design and fabricate high energy density flexible capacitor for microelectronic devices.