Multilayered Piezoelectric Nanogenerator Based on Lead-Free Poly(vinylidene fluoride)-(0.67BiFeO₃-0.33BaTiO₃) Electrospun Nanofiber Mats for Fast Charging of Supercapacitors

Abstract

Polymer-based piezoelectric nanogenerators (PENG) produce satisfactory voltage but low current outputs. Herein, a flexible, multilayered PENG with a high power density is demonstrated based on poly­(vinylidene fluoride) (PVDF)-[0.67­(BiFeO3)-0.33­(BaTiO3)] (BF33BT) electrospun nanofiber mats. With a maximum β-phase and piezoresponse, the optimized composite with 30 wt % BF33BT was used to fabricate the multilayered PENG (MPENG). The MPENG, comprising three layers, shows an open-circuit voltage, short-circuit current, and instantaneous power density of 83 V, 1.62 μA, and 142 mW m–2, respectively, by applying a compressive force of 0.1 kgf at 3 Hz frequency. This power density is almost three times more than that of a single-layer composite-based PENG and 65 times more than that of a single-layer PENG of pristine PVDF. The exceptional piezoresponse is due to the combined effect of the piezoceramic and multilayered structures. The MPENG was used to charge a supercapacitor (0.047 F) up to 1.5 V in 660 s to power a calculator. The device showed no performance degradation for more than 5000 cycles, thus opening up promising avenues for sustainable energy harvesting applications.

Bifunctional NiFe LDH as a piezoelectric nanogenerator and asymmetric pseudo-supercapacitor

“…, and their piezoelectric properties were analyzed. 9,12,23–25 These piezoelectric materials have much smaller values of the piezoelectric charge coefficient, which hinders their application in high piezoelectric nanogenerator applications. But here, we observed a d 33 of 274 pm V −1 .…”

“…Recently, various piezoelectric materials like BiFeO 3 (2.6 pm V À1 ), ZnS nanowire (À17 pm V À1 ), NaNbO 3 nanowire (4.26 pm V À1 ), PZT nanowire (152 pm V À1 ), and Zn 2 SiO 4 nanorods (117 pm V À1 ) were synthesized using sol-gel method, hydrothermal method, chemical vapor deposition method, chemical epitaxial growth method, etc., and their piezoelectric properties were analyzed. 9,12,[23][24][25] These piezoelectric materials have much smaller values of the piezoelectric charge coefficient, which hinders their application in high piezoelectric nanogenerator applications. But here, we observed a d 33 of 274 pm V À1 .…”

“…This self-induced poling effect is due to the piezoelectric as well as capacitive nature of the NiFe LDH nanostructure. 9,26 The piezoelectric effect gives rise to the creation of a negative potential across the platinum side and a similar positive potential across the ITO\PET (counter) electrode of the nanogenerator. These equal and opposite charges create the piezoelectric potential across the electrodes, which drift the electrons from the anode to the cathode in the outer circuit, resulting in the positive current response.…”

“…The piezoelectric performance of the nanogenerator can be improved via several strategies like surface modification, polymerization with polymers, plasma etching. 9 These nanogenerators fabricated using inorganic piezoelectric materials can only tolerate very small strain due to their brittle nature, which restricts their use in sustainable, robust, bio-compatible devices where stability is the measure of concern. Therefore, flexible piezoelectric nanogenerators fabricated using inorganic and organic materials with high durability is a growing research field.…”

Synergistic effect of graphene on dielectric and piezoelectric characteristic of PVDF‐(BZT‐BCT) composite for energy harvesting applications

“…This peak corresponds to the β-phase of PVDF and indicates the formation of the electroactive β-phase of PVDF in all the composite samples. [37][38][39] XRD patterns of all the three phase composites show both PVDF phase and BZT-BCT phase, but the characteristic peaks of GO and rGO are not prominent in their respective groups due to low concentrations of GO and rGO. 21 Further, to estimate the fraction of β-phase of PVDF, FTIR spectra were analyzed.…”