Mechanical energy driven wireless charging technology has recently gained increasing attention. High-performance potassium sodium niobate (KNN) based texture ceramics and its potential application on energy harvesting device are the first...

A synergistic optimization strategy with regard to ferroelectric domain and band structure is applied to NaNbO3 (NN)-based ceramics. High Wrec and η of 7.33 J cm−3 and 83.68% are achieved simultaneously.

The mechanical properties of ultrahigh molecular weight polyethylene (UHMWPE) fibers reinforced rigid polyurethane (PU) composites were studied, and the effects of the fiber surface treatment and the mass fraction were discussed. Chromic acid was used to treat the UHMWPE fibers, and polyurethane composites were prepared with 0.1 to 0.6 wt% as-received and treated UHMWPE fibers. Attenuated total reflection Fourier transform infrared demonstrated that oxygen-containing functional groups were efficiently grafted to the fiber surface. The mechanical performance tests of the UHMWPE fibers/PU composites were conducted, and the results revealed that the treated UHMWPE fibers/PU composites had better tensile, compression, and bending properties than as-received UHMWPE fibers/PU composites. Thermal gravimetric analyzer showed that the thermal stability of the treated fiber composites were improved. The interface bonding of PU composites were investigated by scanning electron microscopy and dynamic mechanical analysis, and the results indicated that the surface modification of UHMWPE fiber could improve the interaction between fiber and PU, which played a positive role in mechanical properties of composites.

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To meet the requirements of environmental friendliness, high-performance lead-free piezoelectric materials have become important materials for next-generation electronic devices. Here, lead-free and potassium-free NaNbO3 (NN)-based ceramics with high piezoelectric (d 33 = 361 ± 10 pC/N) and dielectric (εr = 4500) properties were obtained by tolerant preparation techniques. The excellent piezoelectric and dielectric properties can be attributed to the relaxor morphotropic phase boundaries (R–MPB) and coexisting domain regions, which are beneficial in lowering the free energy and greatly improving the dielectric response and domain switching capability. Furthermore, the d 33 of NaNbO3-10Ba(Ti0.7Sn0.3)O3-1.5NaSbO3 (NN-10BTS-1.5NS) ceramics can be maintained at 350 pC/N over the range of 25–80 °C with a change rate of less than 10%, exhibiting excellent temperature stability. Based on a series of in situ characterizations, the variations of the phase and domain structures of NN-based relaxor piezoelectric ceramics with temperature are clearly demonstrated. This work not only proposes new materials for sensors and actuators but also provides an excellent strategy for designing high-performance piezoelectric ceramics through phase and domain engineering.

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