Dielectric and energy harvesting properties of FeTiNbO₆/PVDF composites with reinforced sandwich structure

Abstract

Flexible dielectrics have been the major enabler for a number of applications in advanced electronic and electrical power systems. As an important flexible dielectric material, polymer composites are promising in raising the poor dielectric properties of neat polymer of current use. In this study, a class of topological‐structure modulated multilayer composites comprising a percolation layer (FeTiNbO6[FTN]/polyvinylidenefluoride [PVDF]) intercalated between two insulating layers (PVDF or BaTiO3[BT]/PVDF) are assembled into sandwich structures by a facile hot‐pressing method. For the prepared sandwich structure, FTN/PVDF film acts as a semiconductive layer to raise dielectric permittivity, while two insulating layers at top and bottom of composite are used to suppress conductivity and dielectric loss. Resulted from the unique performances of the FTN/PVDF film and strong interfacial polarization, the sandwich composite possesses improved dielectric and insulation properties. Moreover, compared with FTN/PVDF, the BT20‐FTN40‐BT20 has lower dielectric loss and higher insulation properties, and after poling at 20 kV/mm for 6 h, it exhibits excellent vibration energy harvesting properties in cantilever mode. Thus, a piezoelectric energy harvester constructed from this sandwich composite can be used for self‐driving wireless sensors. POLYM. COMPOS., 40:E570–E578, 2019. © 2018 Society of Plastics Engineers

Energy harvesting with flexible piezocomposite fabricated from a biodegradable polymer

“…Surface and volume power density as shown in Table 2 are found to be remarkably high (51.12 μW/cm 2 , 2556 μW/cm 3 ). The power density obtained for PCL‐biodegradable is almost comparable to previously reported well‐known composites energy harvester 5,31‐40 …”

Enhanced Energy Storage Performance of Lead-Free Capacitors in an Ultrawide Temperature Range via Engineering Paraferroelectric and Relaxor Ferroelectric Multilayer Films

“…At 1 kHz, it is found that the dielectric constant of the optimum multilayer exhibits the medium value rather than the highest value and the dielectric loss of the samples is less than 0.2 in the frequency range. Normally, it is expected that the difference in conductivity and dielectric constant between BST and BT–BMZ would generate concentrated charges at the interface and thus induce dielectric constant increase as N increases. − However, in real materials, the interfaces are usually not ideally sharp and local ion intermixture exists across the interfaces. In this case, as thickness of the component layer decreases, the effect of the ion intermixture at the interfaces becomes obvious and the interface polarization becomes indistinct, which finally induces the bound charge decrease and reduces the dielectric constant .…”

A Review on PVDF Nanofibers in Textiles for Flexible Piezoelectric Sensors

“…35 To obtain good piezoelectric properties and flexibility, piezo-electric composites are usually prepared by combining ceramic filler and piezoelectric polymer. 36 BaTiO 3 (BT/BTO) has attracted much attention in recent years as an easily handled and environmentally friendly inorganic filler. Among the piezoelectric composites, PVDF/BTO nanocomposites have been widely studied in energy harvesting and flexible sensors because of their simple preparation process, low cost, and good piezoelectric properties.…”