Improving the performance of flexible composites based on 3-3 interconnected skeletons for piezoelectric energy harvesting

• Published in: Ceramics international 2023-07, Vol.49 (14), p.23349-23357
• Main Authors: Li, Jing, Ma, Weibing, Wang, Shenghui, Guo, Jingdong, Hong, Jingnan, Yang, Sen
• Format: Article
• Language: English
• Subjects: 3-3 piezoelectric composites; Energy harvesting; Flexible; High d33 value
• ISSN: 0272-8842
• DOI: 10.1016/j.ceramint.2023.04.167

With the rapid development of microelectronics and portable devices, flexible piezoelectric electricity generators (FPEGs) as self-powered devices have attracted extensive attention. Piezoelectric ceramic-polymer composites with good flexibility is the core component of FPEGs. Having high d33 and g33 values is also essential for power generation. Herein, the porous ceramic skeleton is prepared using PZT based as the ceramic powder and polyurethane sponge as the template, followed by compounding the porous ceramic skeleton with polydimethylsiloxane (PDMS) by vacuum impregnation to prepare a 3-3 interconnected composite. When the ratio of ceramic phase in the ceramic slurry is 75 wt%, the volume fraction of the ceramic phase in the composite can achieve 37 vol%. Before compounding PDMS, porous ceramics are polarised, which is called pre-polarisation. The d33 value of the pre-polarised composites can reach 158 pC/N as compared to not polarising the porous ceramic and then polarising it after composite; the improvement is 48%. In addition, the g33 value of the pre-polarized composites is up to 144 mV m/N. Moreover, the 3.0 × 1.2 × 0.2 cm3 FPEG can generate a maximum output voltage of 15 V and a maximum short circuit current of 167 nA at 9% compression strain. The maximum instantaneous power density is 990 nW/cm2, thereby providing a new idea for piezoelectric power generation.