Defect Engineering with Rational Dopants Modulation for High-Temperature Energy Harvesting in Lead-Free Piezoceramics.

High temperature piezoelectric energy harvester (HT-PEH) is an important solution to replace chemical battery to achieve independent power supply of HT wireless sensors. However, simultaneously excellent performances, including high figure of merit (FOM), insulation resistivity (ρ) and depolarization temperature (T) are indispensable but hard to achieve in lead-free piezoceramics, especially operating at 250 °C has not been reported before. Herein, well-balanced performances are achieved in BiFeO-BaTiO ceramics via innovative defect engineering with respect to delicate manganese doping.

An Intragranular Segregation Structure Enables an Excellent Energy Storage Performance in Composite Dielectrics through Delayed Saturation Polarization.

An electrostatic capacitor for energy storage is an important basic component of pulse power electronics. The electrical breakdown strength () of normal ferroelectrics is low, which limits their application in dielectric energy storage. Constructing a 0-3-type composite dielectric, that is, introducing an insulating metallic oxide into the ferroelectric matrix, can greatly enhance .

Realizing Outstanding Energy Storage Performance in KBT-Based Lead-Free Ceramics via Suppressing Space Charge Accumulation.

The great potential of KBiTiO (KBT) for dielectric energy storage ceramics is impeded by its low dielectric breakdown strength, thereby limiting its utilization of high polarization. This study develops a novel composition, 0.83KBT-0.

Optimizing Output Power Density in Lead-Free Energy-Harvesting Piezoceramics with an Entropy-Increasing Polymorphic Phase Transition Structure.

It is an urgent need to develop lead-free piezoelectric energy harvesters (PEHs) to address the energy dilemma and meet environmental protection requirements. However, the low output power densities limit further promotion of lead-free PEHs for use in daily life. Here, an entropy-increasing strategy is proposed to achieve an increased output power density of 819 μW/cm in lead-free potassium sodium niobate (KNN)-based piezoceramics by increasing the configuration entropy and realizing nearly two times the growth compared with low-entropy counterparts.

Significantly Enhanced Poling Efficiency of Piezocomposites by Tuning Resistivity of a Polymer Matrix.

Although the ability to convert biomechanical vibrations into electric energy has been demonstrated in organic-inorganic piezocomposites, it is challenging to improve their piezoelectric properties owing to insufficient electric field poling. Here, we propose a facile and effective approach to enhance the poling efficiency of a barium calcium zirconate titanate/polydimethylsiloxane (BCZT/PDMS) composite by introducing copper nanowires (Cu NWs) to tune the resistivity of the PDMS matrix. The Cu NW-modified PDMS weakens the resistivity mismatch between the BCZT filler and the PDMS matrix, allowing a higher poling electric field to be applied to the BCZT filler during poling.

Enhanced Piezo-Photocatalytic Performance of NaBiTiO by High-Voltage Poling.

The internal electric field within a piezoelectric material can effectively inhibit the recombination of photogenerated electron-hole pairs, thus serving as a means to enhance photocatalytic efficiency. Herein, we synthesized a NaBiTiO (NBT) catalyst by the hydrothermal method and optimized its catalytic performance by simple high-voltage poling. When applying light and mechanical stirring on a 2 kV mm poled NBT sample, almost 100% of Rhodamine B solution could be degraded in 120 min, and the reaction rate constant reached as high as 28.

Sol-gel research in China: a brief history and recent research trends in synthesis of sol-gel derived materials and their applications.

The sol-gel process has become a rapidly growing research area in materials science. A variety of materials prepared via sol-gel routes have shown unique properties and characteristics that are difficult to achieve using conventional methods. In recent years, tremendous progress in sol-gel R&D has been made not only in the world but also in China.

Two-Step Regulation Strategy Improving Stress Transfer and Poling Efficiency Boosts Piezoelectric Performance of 0-3 Piezocomposites.

The rapid development of flexible micropower electronics has aided the opportunity for the broader application of flexible piezoelectric composites (PCs) but has also led to higher requirements for their power generation. Among them, 0-3 PCs with embedded zero-dimension piezoparticle fillers, although low cost and easy to prepare, suffer from suboptimal output performance because of inherent structural defects. In this work, the voltage output was increased from 3.

Multiscale Heterogeneity Strategy in Piezoceramics for Enhanced Energy Harvesting Performances.

Piezoelectric energy harvesters (PEHs) with piezoceramics as the core can convert low-frequency vibration energy that is ubiquitous in the environment into electrical energy and are at the frontier of research in the field of energy. The high piezoelectric charge coefficient () together with the large piezoelectric voltage coefficient () are essential for enhancing the energy harvesting performances of PEHs working on a nonresonant state. However, conventional doping and solid solution design strategies lead to the same increase or decrease trend of and dielectric permittivity ε, making it difficult to obtain a high value because = /ε.

Flexible piezoelectric energy harvester with an ultrahigh transduction coefficient by the interconnected skeleton design strategy.

Based on the strong demand for self-powered wearable electronic devices, flexible piezoelectric energy harvesters (FPEHs) have recently attracted much attention. A polymer-based piezocomposite is the core of an FPEH and its transduction coefficient (d×g) is directly related to the material's power generation capacity. Unfortunately, the traditional 0-3 type design method generally causes a weak stress transfer and poor dispersion of the filler in the polymer matrix, making it difficult to obtain a high d×g.

High performance piezocomposites for flexible device application.

Flexible piezocomposites have emerged as promising materials for highly durable wearable devices. Here, we propose a new design strategy, namely particle alignment engineering, to develop high performance flexible piezocomposites by dielectrophoresis (DEP). An ultrahigh piezoelectric voltage coefficient (g33) of 600 × 10-3 V m N-1 is achieved by a composite of (Ba0.

Flexible Piezoelectric Energy Harvester with Extremely High Power Generation Capability by Sandwich Structure Design Strategy.

In order to achieve a high-performance flexible piezoelectric energy harvester (FPEH), a unique sandwich structure, that is, a PVDF film filled with FeTiNbO (FTN) semiconductor particles as an intermediate layer and a pure PVDF film as an upper and lower barrier layer, has been designed, and the corresponding PVDF-FTN/PVDF-PVDF (P-FTN-P) compact composite has been prepared by hot-pressing technology. The special sandwich structure combined with the introduction of FTN particles is beneficial to enhance the interfacial polarization and the content of the electroactive phase in PVDF. Together with the maximum piezoelectric voltage coefficient and the moderate Young's modulus, the P-FTN15%-P FPEH exhibited the optimal energy-harvesting performance with a high power density of 110 μW/cm and a large charge density of 75 μC/m in cantilever mode.

Boosting energy harvesting performance in (Ba,Ca)(Ti,Zr)O lead-free perovskites through artificial control of intermediate grain size.

In this study, (Ba0.85Ca0.15)(Ti0.

Composition-induced phase evolution and high strain response in Ba(ZnNb)O-modified (BiNa)TiO-based lead-free ferroelectrics.

In this work, a paraelectric complex perovskite Ba(ZnNb)O (BZN) was introduced into the morphotropic boundary composition (BiNa)BaTiO (BNBT) to modulate the phase structure and electrical properties as well as the field-induced strain behavior. Using a columbite route, the ceramics with pure perovskite structure were successfully fabricated. The structure and electrical measurements showed that the introduction of BZN into BNBT results in the decrease of the rhombohedrality 90-, and promotes the evolution from ferroelectric to antiferroelectric (AFE) relaxor.

Improving Dielectric Properties of PVDF Composites by Employing Surface Modified Strong Polarized BaTiO₃ Particles Derived by Molten Salt Method.

BaTiO3/polyvinylidene fluoride (BT/PVDF) is the extensive reported composite material for application in modern electric devices. However, there still exists some obstacles prohibiting the further improvement of dielectric performance, such as poor interfacial compatibility and low dielectric constant. Therefore, in depth study of the size dependent polarization and surface modification of BT particle is of technological importance in developing high performance BT/PVDF composites.

Dielectric, piezoelectric, and ferroelectric properties of MnCO3-added 74(Bi(1/2)Na(1/2)) TiO3-20.8(Bi(1/2)K(1/2))TiO3-5.2BaTiO3 lead-free piezoelectric ceramics.

74(Bi(1/2)Na(1/2))TiO3-20.8(Bi(1/2)K(1/2))TiO3-5.2BaTiO3-x MnCO3 lead-free piezoelectric ceramics were synthesized by conventional solid oxide routine.

Facile synthesis and high d33 of single-crystalline KNbO3 nanocubes.

Single-crystalline KNbO(3) nanocubes with orthorhombic phase were prepared in a large scale by a simple one-step molten salt route without using any surfactant as template; the nanostructures exhibited high piezoelectric properties such as d(33)=105 pC/N and k(p)=0.34 as piezoelectric materials.

[Raman scattering studies on 0.5PZN-0.5PZT piezoceramics].

PZT based multi-system has shown super piezoelectric properties when the composition was located at morphotropic phase boundary (MPB), which divided the regions into rhombohedral and tetragonal structures equally. In the present paper, the diffuse phase transition and phase coexistence of rhombohedral and tetragonal phases of 0.5PZN-0.