Enhancement in energy storage and piezoelectric performance of three phase (PZT/MWCNT/PVDF) composite

Abstract

The conversion of mechanical energy (vibration) to electrical signal (voltage/power) is one of the versatile phenomena in energy harvesting process. In the effort to develop self-powered devices that will convert readily available vibrations into electrical power and no external source of energy will be required for operation, a three phase hybrid piezoelectric nanogenerator comprising of Lanthanum doped Lead Zirconate Titanate (PLZT), Polyvinyldene fluoride (PVDF) and Multi-walled Carbon Nanotubes (MWCNT) as supplement filler was fabricated. Piezoelectric composite films were prepared using tape casting technique, followed by hotpress. The addition of PLZT to PVDF and further MWCNT in PLZT-PVDF composite resulted in the enhancement of dielectric, ferroelectric, piezoelectric and energy storage properties. A maximum open circuit AC peak-to-peak voltage of 20 V was obtained from the nanogenerator after applying repeated human figure tapping and releasing motion on the sample. After rectification of the output AC voltage by bridge rectifier, the DC voltage was able to charge a 40 μF commercial capacitor up to 8 V (2 mW power) and during discharging of the capacitor, around 50 LEDs were glowed. A 40 μF capacitor was also charged by using the same method after applying foot pressure on the nanogenerator which delivered 1.5 mW power with 6 V DC voltage and 250 μA short circuit current. Thus the amount of power delivered by the fabricated nanogenerator can drive several LEDs and charge capacitor which can be used for powering small electronic devices.