Electrical and mechanical behavior of PMN-PT/CNT based polymer composite film for energy harvesting

Highlights: • A pyrochlore free PMN-PT/CNT/PVDF based piezoelectric flexible composite film has been fabricated. • Maximum output voltage and current generated by 30vol.%PMN-PT/CNT/PVDF composite is ∼4 V and 30 nA, respectively. • A significant improvement in permittivity at low frequency and high temperature with a minimal dielectric loss. • An increase in Young's modulus of the composite to 705 MPa as compared to 597 MPa in pure PVDF. The pyrochlore-free 30-PMN-PT/CNT/PVDF based piezoelectric flexible composite film has been synthesized for potential application in piezoelectric energy harvesting. Electrical characterization reveals that the maximum output voltage and current generated by the 30 vol.% PMN-PT/CNT/PVDF composite is ∼4 V and 30 nA respectively, comparable with the available literature. Further, impedance analysis has revealed a significant improvement in permittivity at low frequency and high temperature with a minimal dielectric loss. AC conductivity behavior fits well with Johnscher's universal power law that predicts the motion of the charge carriers is translational with sudden hopping. The Nyquist plots indicate the contributions of both grain and grain boundaries at lower temperature (25–100 °C) and additional electrode effect of higher temperature (100–150 °C) on the capacitive and resistive properties of the composite. Mechanical characterization of the composite shows an increase in Young's modulus of 705 MPa compared to 597 MPa in pure PVDF.