Design and Piezoelectric Energy Harvesting Properties of a Ferroelectric Cyclophosphazene Salt

Abstract

Cyclophosphazenes offer a robust and easily modifiable platform for a diverse range of functional systems that have found applications in a wide variety of areas. Herein, for the first time, it reports an organophosphazene‐based supramolecular ferroelectric [(PhCH2NH)6P3N3Me]I, [PMe]I. The compound crystallizes in the polar space group Pc and its thin‐film sample exhibits remnant polarization of 5 µC cm−2. Vector piezoresponse force microscopy (PFM) measurements indicated the presence of multiaxial polarization. Subsequently, flexible composites of [PMe]I are fabricated for piezoelectric energy harvesting applications using thermoplastic polyurethane (TPU) as the matrix. The highest open‐circuit voltages of 13.7 V and the maximum power density of 34.60 µW cm−2 are recorded for the poled 20 wt.% [PMe]I/TPU device. To understand the molecular origins of the high performance of [PMe]I‐based mechanical energy harvesting devices, piezoelectric charge tensor values are obtained from DFT calculations of the single crystal structure. These indicate that the mechanical stress‐induced distortions in the [PMe]I crystals are facilitated by the high flexibility of the layered supramolecular assembly.

Multiaxial Multiferroicity with Large Spontaneous Polarization in a Hydroxyl-Modified Quinuclidinium Gallium(III) Chloride

“…To demonstrate the excellent ferroelectric properties of R3HQGC , we compared the P s value of R3HQGC with the selected multiaxial ferroelectric (containing the selected hybrid multiferroics). As shown in Table , ,,− the polarization value of R3HQGC is higher than most organic–inorganic hybrid multiaxial ferroelectrics and is the largest in metal halide hybrid multiferroics. Piezoelectric-force microscopy (PFM) has become a mainstream method for characterizing ferroelectric properties at the nanoscale.…”

Triboelectric nanogenerator based on electrospun molecular ferroelectric composite nanofibers for energy harvesting

“…, thermoelectric, piezoelectric, electromagnetic, pyroelectric and triboelectric). 6–14 Among several energy-harvesting technologies being explored, triboelectric nanogenerators (TENGs) hold great promise because of their extensive versatility. Ease of fabrication, distinct device design, wide array of material availability and remarkable power-conversion efficiencies render them highly attractive towards the escalating problems that the energy sector is facing.…”