Fully Rollable Lead-Free Poly(vinylidene fluoride)-Niobate-Based Nanogenerator with Ultra-Flexible Nano-Network Electrodes

Abstract

A fully rollable nanocomposite-based nanogenerator (NCG) is developed by integrating a lead-free piezoelectric hybrid layer with a type of nanofiber-supported silver nanowire (AgNW) network as electrodes. The thin-film nanocomposite is composed of electroactive polyvinylidene fluoride (PVDF) polymer matrix and compositionally modified potassium sodium niobate-based nanoparticles (NPs) with a high piezoelectric coefficient ( d) of 53 pm/V, which is revealed by the piezoresponse force microscopy measurements. Under periodical agitation at a compressive force of 50 N and 1 Hz, the NCG can steadily render high electric output up to an open-circuit voltage of 18 V and a short-circuit current of 2.6 μA. Of particular importance is the decent rollability of the NCG, as indicated by the negligible decay in the electric output after it being repeatedly rolled around a gel pen for 200 cycles. Besides, the biocompatible NCG can potentially be used to scavenge biomechanical energy from low-frequency human motions, as demonstrated by the scenarios of walking and elbow joint movement. These results rationally expand the feasibility of the developed NCG toward applications in lightweight, diminutive, and multifunctional rollable or wearable electronic devices.

Performance Enhancement of Flexible Piezoelectric Nanogenerator via Doping and Rational 3D Structure Design For Self‐Powered Mechanosensational System

“…When the concentration of the piezoelectric fillers was increased from 10 to 30 wt% in the silicone rubber matrix, the V OC and I SC were boosted from 2 to 16 V and 0.5 to 2.8 µA, respectively. The remarkable reinforcement of the output performance is assigned to the enhanced piezoelectricity of the piezocomposites, which originated from the well‐known interfacial or Maxwell–Sillars polarization occurring at the interfaces between the inorganic piezoelectric fillers and organic silicone rubber matrix . Nevertheless, as the amount of the piezoelectric filler was further increased to 40 wt%, the V OC and I SC were dropped to 10 V and 1.8 µA, respectively.…”

“…The polarization orientation of each domain is inclined to align along the electric field direction through the motions of domain wall in the event of the high electric field poling applied to the PENG. In this circumstance, no output electrical signal will be detected provided that no external force was acted on the PENG device (Figure S6b, Supporting Information) . When the PENG is subjected to vertical compressive pressure, a piezopotential is created across the bottom and top electrodes in virtue of the broken electrostatic equilibrium state and the altered total polarization in the piezocomposite film .…”

Hybrid lead-free polymer-based nanocomposites with improved piezoelectric response for biomedical energy-harvesting applications: A review

“…A KNN/PVDF-based NG exposed to a vibrational load with a compressive force of 50 N and a frequency of 1 Hz was shown to generate an output voltage of up to 18 V and a current of up to 2.6 μA [54]. Kang et al studied the energy harvesting performance of a nanocomposite based on a PVDF-TrFE matrix filled with perovskite KNN NPs ranging from 30 to 105 nm in size [12].…”

High‐performance poly(vinylidene fluoride)‐polyamide 11/lithium niobate nanocomposites for the applications in air filtration

“…However, the former has the disadvantage of low mechanical strength while the latter has the shortcoming of low mechanical toughness. In contrast, polymer electrets [e.g.,poly(vinylidene fluoride) (PVDF), polyamide 11 (PA11), and polypropylene (PP)] are both mechanically strong and mechanically flexible . Besides, these polymer materials also have other advantages such as low mass density, easy processing, and low cost .…”