Progress in lead-free piezoelectric nanofiller materials and related composite nanogenerator devices

Abstract

This report is a representative review article which deeply describes lead-free piezoelectric nanofillers and related composite nanogenerator devices.

Hydrogel Ionic Diodes toward Harvesting Ultralow‐Frequency Mechanical Energy

“…[ 1–3 ] Among various potential energy sources, mechanical energy is one of the most pervasive types in our life and environment. [ 4–6 ] The harvesting of mechanical energy enables many applications such as wearable and in vivo medical devices where solar or other forms of ambient energy are not efficient. [ 7,8 ] Although a variety of piezoelectric, triboelectric, and electromagnetic energy harvesters have been extensively developed to capture mechanical energy, the current devices still suffer from a number of critical drawbacks, including inefficiency at low frequencies, low charge amounts, and seriously high matching resistance.…”

Up-scalable emerging energy conversion technologies enabled by 2D materials: from miniature power harvesters towards grid-connected energy systems

“…10c). 310 In this configuration, the piezoelectric 2D material acts as the nanofillers of the final composite structure, 311 while the optimized mechanical structure of the metal electrodes (panel I) using symmetric design of serpentine patterns on both sides of the electrodes (panel II) led to excellent stretchability even when mounted on the skin without exhibiting any irritation (panels III and IV). In particular, the graphene embedded ternary composite exhibited a maximum power density of 972.43 mW cm À3 under human walking, while demonstrating excellent mechanical tolerance to bending, stretching, and twisting for thousands of cycles.…”

Ferroelectric Polymer Nanofibers Reminiscent of Morphotropic Phase Boundary Behavior for Improved Piezoelectric Energy Harvesting

“…The PDMS was used as an encapsulation matrix and/or additional dielectric layers for mechanical, electrical, and chemical stability in many pervious piezoelectric energy harvesters. [13,[87][88][89][90] In particular, it is highly important to avoid electrical breakdown during an external poling process although dielectric loss factor may slightly dissipate energy harvesting performance. The schematics of piezoelectric energy harvesting with dielectric contents is also illustrated in Figure S14 (Supporting Information).…”

“…[5][6][7][8][9][10][11][12] While piezoelectric ceramic materials have primarily been considered, their various drawbacks, including their restricted scalability, brittleness, difficulty in controlling their composition, and the biocompatibility problems associated with their Pb components-have prompted a number of researchers to introduce polyvinylidene fluoride (PVDF)-based polymer materials as an alternative. [13][14][15][16][17][18] PVDF materials, which are ferroelectric and piezoelectric polymers with an electroactive β phase induced by a strong -CF 2 -dipole, [19,20] are reliably biocompatible, excellent processibility, and offer high chemical resistance with mechanical Ferroelectric and piezoelectric polymers have attracted great attention from many research and engineering fields due to its mechanical robustness and flexibility as well as cost-effectiveness and easy processibility. Nevertheless, the electrical performance of piezoelectric polymers is very hard to reach that of piezoelectric ceramics basically and physically, even in the case of the representative ferroelectric polymer, poly(vinylidene fluoride-co-trifluoroethylene) (P(VDF-TrFE)).…”