Degradable flexible piezoelectric nanogenerator based on two-dimensional barium titanate nanosheets and polylactic acid

Abstract

With the increasing demand for green energy, piezoelectric nanogenerators (PNGs) have attracted extensive attention in energy harvesting. In this work, a high-performance PNG was successfully fabricated from BaTiO₃ (BT) and polylactic acid (PLA) via a spin-coating process. Among these materials, high aspect ratio BT nanoparticles with a two-dimensional (2D) plate-like morphology synthesised via a solvothermal method significantly enhanced the piezoelectric properties of the BT/PLA nanocomposite. With an increase in the 2D BT content, the piezoelectric properties of the BT/PLA nanocomposite PNG significantly improved. A PNG with 6 wt% BT content exhibited a maximum output voltage of 11.97 V and short-circuit current of 560 nA, showing the ability to charge a commercial capacitor to 3.95 V. In durability testing, the same material effectively harvested energy from human activities and exhibited 2000 cycles of smooth data output. After the use of the PNG, the disassembled BT/PLA nanocomposite film can be completely degraded in a dilute alkaline solution, and the recycled BT can be reused without loss in activity. This study shows the potential application of a flexible 2D BT/PLA nanocomposite in human motion monitoring, smart skin, and soft robotics. Moreover, it provides an ingenious idea for dealing with waste PNG devices and reusing piezoelectric fillers.