Inducing Polar Phase in Poly(Vinylidene Fluoride) with a Molecular Ferroelectric Copper(II) Complex for Piezoelectric Energy Harvesting

Abstract Piezoelectric nanogenerators (PENGs), the current pathway to sustainable energy harvesting, are mostly comprised of bulk oxide ceramics which are toxic, rigid, and costly to synthesize. A suitable alternative to them is flexible polar polymers like polyvinylidene fluoride (PVDF), but stabilizing its polar phase is also a daunting task. all these aforementioned issues by employing a biocompatible have been solved, above‐room‐temperature ( T c > 390 K) ferroelectric discrete molecular complex [Cu(L‐His)(bpy)]ClO 4 .1.5H 2 O ( Cu‐FE ) which is not only suitable for piezoelectric energy harvesting due to its large values of piezoelectric co‐efficient (d 33 = 17 pm V −1 ) but also is capable of imparting polar β ‐phase in PVDF via hydrogen bonding interactions under mild condition (60 °C). Among the PENG devices prepared with the composite films of PVDF and various weight % (w/V) compositions of Cu‐FE , the highest output voltage of 8 V (peak to peak) has been obtained, a power density of 4 µW cm −2 , and an output current of 3 µA from the 1 wt.% composite film. The fabricated PENG device also exhibits swift capacitor charging in 40 s, and acts as an excellent pressure sensor, with exceptional sensitivity to low pressures (7 kPa), giving an output of 0.4 V.