Liquid Electrolyte-Assisted Electrospinning for Boosting Piezoelectricity of Poly (vinylidene Fluoride) Fiber Mats

Piezoelectric polymer films are forthcoming choices for self-powered portable flexible electronics due to instant mechanoelectrical transduction, ease of fabrication, and assembly for device integration. However, the low piezoelectricity of polymers in comparison with piezoelectric ceramics precludes their practical applications significantly. Here, we report an interesting method to fabricate piezoelectric poly(vinylidene fluoride) (PVDF) fiber mats with excellent piezo-electricity by collecting electrospun fibers using low-temperature electrolytes. Specifically, fiber collection assisted by liquid electrolytes enables the formation of piezoelectric PVDF crystals with zigzag conformation induced by strong solvent- electrolyte and dipole-ion interactions, as well as the immobilization of aligned dipoles at low temperature. Consequently, compared with conventional PVDF fibers collected by aluminum foils, those fiber mats electrospun using liquid electrolytes can generate an open-circuit voltage of 2.3 V under a pressure of 20 N at 1 Hz for an effective area of 1 cm(2), showing a nearly eight-times improvement. In addition, the as-prepared piezoelectric fiber mats enable the conversion of mechanical energy into electricity with an instantaneous output power density of similar to 16.2 mW/m(2), which allows for self-powered sensing or energy harvesting. Such an electrospinning technology enables simple fabrication of high-performance piezoelectric polymer fiber mats with diverse surface microstructure for self-powered flexible electronics.