Enhanced piezoelectric performance of PVDF/BiCl3/ZnO nanofiber-based piezoelectric nanogenerator

A unique bismuth chloride (BiCl3)/zinc oxide (ZnO)/poly(vinylidene fluoride) (PVDF) nanofiber-based highly flexible piezoelectric nanogenerator (PENG) is prepared via electrospinning technique. Fourier transform infrared spectroscopy (FTIR) and X-ray diffraction (XRD) are used to characterize the β-phase content and crystallinity of the PVDF based nanofibers, respectively. Then, we analyze four types nanofiber-based PENG (PVDF, PVDF/ZnO(2%), PVDF/BiCl3(2%), and PVDF/BiCl3/ZnO(2%)) and the influence factors of piezoelectric properties are addressed systematically. It is found that the longitudinal piezoelectric coefficient (d33) of PVDF/BiCl3/ZnO(2%) nanofiber-based PENG is up to 3.8 pC/N and an open-circuit voltage (VOC) of 12 V is also got. Finally, the practical applicability of the developed PENG is demonstrated by placing it on elbow and knee joint to monitor human body movement, which shows a maximum peak VOC of 3 V (for elbow) and 0.6 V (for knee) by bending and stretching between specific angles. The high-performance flexible PENG can be used as highly sensitive self-powered sensor, and it also can be used for wearable sensors for detecting some vital signals including breathing, heartbeating, which shows its possible applications in wearable electronics.