A novel facile preparation method of self-polarized Poly(vinylidene fluorides) nanofiber for high-performance piezoelectric nanogenerator

Abstract

A new facile preparation technique for self-polarization and alignment without external poling on poly(vinylidene fluorides) (PVDF) nanofiber was demonstrated. The nanofibers were prepared using a fast-centrifugal spinning technique. Formation of high-yield long, smoothed and beads-free fibers with enhanced piezoelectric β-phase was found to be a function of the ratio between solvents (N,N-Dimethylformamide (DMF) and acetone) and rotational speeds. Highest β-phase content and piezoelectric charge coefficient, d33 (95% and 152 pC.N−1 respectively) were achieved when DMF:acetone volume ratio and rotational speed were 3:7 and 8000 rpm, respectively. Under 17.8 kPa vertical stress, pure PVDF fibers-based flexible piezoelectric nanogenerator (PNG) displayed the highest output performances to date with open-circuit voltage, short-circuit current and power density of 22 V, 2.2 μA and 12.6 μW cm−2 respectively. Unique self-polarization characteristics of the fiber achieved via centrifugal spinning technique is the plausible explanation for the current highly durable and outstanding performance of the PNG.