Dramatically enhanced energy harvesting capability in sandwich-structure modulated piezoelectric nanocomposites

Abstract

Piezoelectric energy harvesting devices (PEHs) offer great potential for diverse electronic applications. However, it is still a great challenge to well combine appropriate mechanical strength and high output performance in composite-type PEHs. Herein, the sandwich-structured composite-type PEHs for high-output mechanical energy harvesting using piezoelectric Barium titanate nanoparticles and poly(vinylidenefluoride-co-trifluoroethylene) (P(VDF-TrFE)) copolymers matrix is reported. By intentionally modulating the distribution of piezoelectric nanoparticles in polymer matrix, a highest output of ∼60 V (open-circuit voltage), and ∼65 μW/cm3 (power density at load resistance of 50 MΩ), respectively, was obtained. Via mechanical property and energy harvesting capability quantification, the dramatically improved energy harvesting capability is determined to be stemmed from the stress-enforcement in embedded piezoelectric nanoparticles and optimized piezoelectric response. Besides, the device presents a sufficient mechanical durability, which endows it the ability for long time stable operation. This work sheds light on a universal strategy for fabricating high-performance composite-type PEHs by constructing a gradient distribution of piezoelectric active nanoparticles in polymer matrix.