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Flexible piezoelectric nanogenerators (F-PENG) as a clean, green power generation device have attracted much attention. Dielectrophoresis (DEP) was used to prepare flexible piezoelectric nanogenerators with necklace-like oriented structure. The results showed that the oriented structure significantly improved the electrical output performance of F-PENG by enhancing the stress and free charge transmission. For the F-PENG with 8 vol% oriented PZT particle, open-circuit voltage and short-circuit current reached 176 V and 35 μA and an instantaneous power of up to 2 mW was collected for an optimal matched load resistance of 6 MΩ. Output voltage and current increase by 135% and 133%, respectively, compared with the F-PENG with random structure. Meanwhile, the finite element simulation results also confirmed the superiority of this oriented structure. There was a clear linear relationship between the output voltage and pressure, and the sensitivity was 1.13 N/V. The oriented PZT particle-based F-PENG with excellent electrical output performance has great application prospects in the fields of green power generation and selfpowered building monitoring system.

The polymer dielectric is a promising material for intelligent and energy-saving applications in modern electronic and power systems. However, there are many crucial drawbacks in the applications at elevated temperatures, such as high dielectric loss and low energy density. Herein, a method to enhance the thermal stability of the polymer dielectrics is presented, whereby SrTiO3 particles are introduced into poly­(ether imide) (PEI) film to fabricate polymer-based dielectric composites. SrTiO3 is preferred as the filler for its moderate dielectric constant and wide band gap, which simultaneously restrains the leakage current density of the composites. The results show that the composite dielectric loaded with 3 vol % SrTiO3 particles achieves a discharge energy density of 11.30 J/cm3 at 640 MV/m. Furthermore, it exhibits the highest energy density of 10.30 J/cm3 at 150 °C and 530 MV/m, while the discharge energy density and efficiency remain 8.82 J/cm3 and 80% under 500 MV/m at 150 °C, respectively. The composites exhibit excellent fatigue resistance, and the discharge energy density is maintained at 96.21% with an efficiency of 95.96% after 105 charge–discharge cycles at 150 °C. This work elaborates the feasibility of adding SrTiO3 particles into PEI to enhance high-temperature capacitive properties and the great potential for extensive industrial production.

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