No abstract

The design of an energy-harvesting unit with superior output characteristics, i.e., high power density, is a great technological challenge in the present time. Here, simple, lightweight, flexible, and cost-effective piezoelectric nanogenerators (PENGs) have been fabricated by integrating the aluminum electrodes onto Er/Fe stimulated electroactive, visible-light-emitting, and large dielectric PVDF films in which ErCl·6HO and Fe(NO)·9HO act as the catalytic agents for electroactive β polymorph nucleation and the enhancement of dielectric properties. The developed PENGs exhibit excellent energy-harvesting performance with very high power density and very fast charging ability compared with the previously reported PVDF-assisted prototype nanogenerators. The PENGs lead to very large power density (∼160 and ∼55.34 mW cm) under periodic finger imparting for Er- and Fe-stimulated PVDF-film-based energy-harvester units, respectively. The fabricated self-powered PENG is also able to light up 54 commercially available light-emitting diodes.

A simple, cost-effective and environment-friendly biowaste crab shell-extracted chitin nanofiber-based superior piezoelectric nanogenerator was fabricated in this study.

Herein, we have successfully designed two ecofriendly, biocompatible, and cost-effective devices, i.e., a piezoelectric nanogenerator (PENG) and a self-charged photo-power cell (PPC) by developing a multifunctional cetyltrimethylammonium bromide (CTAB) modified montmorillonite (MMT) incorporated poly­(vinylidene fluoride) (PVDF) thin film with large electroactive β crystallites and dielectric properties. Incorporation of CTAB modified MMT in PVDF leads to nucleation of piezoelectric β crystallite (F(β)) ∼ 91% as well as the dielectric constant ∼48 at 3 mass % doping of CTAB-MMT. The enrichment of the electroactive β phase crystallization and high dielectric constant pilot to a good piezoelectricity (d 33) ∼ 62.5 pC/N at 50 Hz of the thin film. Our CTAB-MMT/PVDF based PENG (CMPENG) with superior piezoelectricity shows high output power generation with power density ∼ 50.72 mW/cm3 under periodic finger impartation and having the ability to charge a 1 μF capacitor up to 2.4 V within 14 s under gentle finger impartation. CMPENG also have the potential to glow up commercially available 26 blue light-emitting diodes (LEDs) connected in series. The self-charged PPC has been designed with the thin film in association with MnO2-MWNT/PVP/H3PO4. Our PPC is able to generate supercilious output voltage ∼ 1.38 V and short circuit current ∼ 3.7 mA/cm2under light illumination with specific areal capacitance and energy storage efficiency of ∼1501 F/m2 and ∼93%, respectively. The realistic application of our PPC is investigated by lighting 24 blue LEDs for 7 days with the same intensity by charging the device once for 50 s.

In the present work, we propose a simple and unique approach to design a lightweight, low-cost, self-charging power cell with considerable capacity to generate and store photocharges named self-charged photo-power cell (SCPPC). Initially, highly electroactive sodium dodecyl sulfate (SDS)-incorporated poly-(vinylidene fluoride) (PVDF) composite thin films with a large dielectric constant of ∼525 are synthesized via a simplistic solution casting process. Then, the as-prepared high-dielectric SDS/PVDF thin film is used as a charge-storage medium in combination with an inorganic−organic dye film, i.e., ZnO nanoparticles−eosin Y− poly(vinylpyrrolidone) film, as a photoelectron generator in our SCPPC. An opencircuit voltage of ∼1.2 V is attained after charging SCPPC under illumination light with intensity ∼110 mW/cm 2 and then discharging fully with a constant current density of ∼4.5 mA/cm 2 . A specific areal capacitance of ∼450 F/m 2 is obtained with large energy and power densities of ∼90 mWh/m 2 and 54 W/m 2 , respectively. The improved overall efficiency, ∼3.78%, along with 89% storage efficiency leads to promising application possibilities of our rechargeable photo-power cell. The recyclability, i.e., rechargeability and storage durability, of the photo-power cell are also checked for 35 days without no such reduction in voltage generation and storage. Also, multicolored light-emitting diodes are lightened up using the photo-power cell as power source.