Tailoring mechanical energy harvesting performance of piezoelectric nanogenerator via intrinsic electrical conductivity of ferroelectrics

Abstract Piezoelectric based mechanical energy harvesting has received tremendous attention as an alternative green energy harvesting technology. However, magnitude of power generated in this process is extremely low pertaining to the low current response of piezoelectric energy harvesters (PEHs). While conducting fillers such as Ag nanowire, CNT, Cu nanorods etc have used in conventional piezoelectric/polymer composite devices to increase scavenged power density, achievement is not significant. Finding an alternative and efficient way of tailoring the energy harvesting is therefore highly appreciated. In this article, we introduce the concept of tuning intrinsic electrical conductivity of ferroelectric ceramics while preserving its ferroelectric/piezoelectric strength to enhance energy harvesting performance of piezoelectrics. We implement this idea by developing an electron doped (La-doped) Ba(Sn0.09Ti0.91O3) (BST:La) piezoceramic and further designing 0-3 type composite device with non-ferroelectric polydimethylsiloxane (PDMS) polymer. About 3 order of increase of intrinsic current density in the doped piezoceramic compared to that of undoped component leads to the scavenged power density enhancement ∼10.5 times in the composite with doped specimen as compared to that comprises of undoped piezoceramic (BST). Our approach opens up a new, convenient way to improve power density of piezoelectric based flexible energy harvesters.