Zeng Shi, Zhang Mingrui, Jiang Lei, Wang Zhao, Gu Haoshuang, Xiong Juan, Du Yi, Ren Long
Hubei Key Laboratory of Ferro & Piezoelectric Materials and Devices, Faculty of Physics & Electronic Sciences, Hubei University, Wuhan, Hubei 430062, P. R. China.
BUAA-UOW Joint Research Centre and School of Physics, Beihang University, Beijing 100191, P. R. China.
ACS Appl Mater Interfaces. 2022 Feb 16;14(6):7990-8000. doi: 10.1021/acsami.1c22877. Epub 2022 Feb 2.
High-output flexible piezoelectric nanogenerators (PENGs) have achieved great progress and are promising applications for harvesting mechanical energy and supplying power to flexible electronics. In this work, unique core-shell structured Ga-PbZrTiO (PZT)@GaO nanorods were synthesized by a simple mechanical mixing method and then were applied as fillers in a poly(vinylidene fluoride-trifluoroethylene) (P(VDF-TrFE)) matrix to obtain highly efficient PENGs with excellent energy-harvesting properties. The decoration of gallium nanoparticles on PZT @GaO nanorods can amplify the local electric field, facilitate the increment of polar β-phase fraction in P(VDF-TrFE), and strengthen the polarizability of PZT and P(VDF-TrFE). The interfacial interactions of GaO and P(VDF-TrFE) are also in favor of an increased β-phase fraction, which results in a remarkable improvement of PENG performance. The optimized Ga-PZT@GaO/P(VDF-TrFE) PENG delivers a maximum open-circuit voltage of 98.6 V and a short-circuit current of 0.3 μA with 9.8 μW instantaneous power under a vertical force of 12 N at a frequency of 30 Hz. Such a PENG exhibits a stable output voltage after 6 000 cycles by the durability test. Moreover, the liquid gallium metal offers a mechanical matching interface between rigid PZT and the soft polymer matrix, which benefits the effective, durable mechanical energy-harvesting capability from the physical activities of elbow joint bending and walking. This research renders a deep association between a liquid metal and piezoelectric ceramics in the field of piezoelectric energy conversion, offering a promising approach toward self-powered smart wearable devices.
高输出柔性压电纳米发电机（PENGs）已取得了重大进展，在收集机械能并为柔性电子产品供电方面具有广阔的应用前景。在这项工作中，通过简单的机械混合方法合成了独特的核壳结构Ga-PbZrTiO（PZT）@GaO纳米棒，然后将其用作聚（偏二氟乙烯-三氟乙烯）（P（VDF-TrFE））基体中的填料，以获得具有优异能量收集性能的高效PENGs。在PZT@GaO纳米棒上装饰镓纳米颗粒可以放大局部电场，促进P（VDF-TrFE）中极性β相分数的增加，并增强PZT和P（VDF-TrFE）的极化率。GaO与P（VDF-TrFE）的界面相互作用也有利于β相分数的增加，这导致PENG性能的显著提高。优化后的Ga-PZT@GaO/P（VDF-TrFE）PENG在12 N的垂直力、30 Hz的频率下，可提供98.6 V的最大开路电压和0.3 μA的短路电流，瞬时功率为9.8 μW。通过耐久性测试，这种PENG在6000次循环后表现出稳定的输出电压。此外，液态镓金属在刚性PZT和软聚合物基体之间提供了机械匹配界面，这有利于从肘关节弯曲和行走的身体活动中有效、持久地收集机械能。这项研究在压电能量转换领域建立了液态金属与压电陶瓷之间的深入联系，为自供电智能可穿戴设备提供了一种有前景的方法。
