Highly-flexible piezoelectric nanogenerators with silver nanowires and barium titanate embedded composite films for mechanical energy harvesting

다국어 초록 (Multilingual Abstract)

<P><B>Abstract</B></P> <P>Piezoelectric nanogenerators (PNGs) is one of the promising technologies to convert mechanical energies into electricity for driving various mobile/portable electronic devices. Generally, the electrical output performance of PNGs is enhanced by electrical poling or annealing treatment, which involves high voltage and temperature techniques. Herein, we successfully demonstrated a flexible PNG designed by the barium titanate embedded polyvinylidene difluoride (i.e., BaTiO<SUB>3</SUB>/PVDF) composite film and attained a significant output performance with avoiding electrical poling process. These barium titanate micro stone-like architectures (BTO-MSs) were synthesized by a facile, eco-friendly, and cost-effective solid-state reaction. In addition, the output performance of PNG is further improved by dispersing the silver nanowires (Ag-NWs) as a conducting supplement filler along with the BTO-MSs into the PVDF matrix. Resultantly, the PNG with Ag-NWs/BTO/PVDF composite film exhibited a high open-circuit voltage (V<SUB>OC</SUB>) of ∼ 14 V and short-circuit current (I<SUB>SC</SUB>) of ∼ 0.96 μA compared to the PNG with only BTO/PVDF (V<SUB>OC</SUB>/I<SUB>SC</SUB> ∼ 11 V/0.78 μA) upon the application of a low pushing force of 3 N, cyclic pushing-releasing frequency of 5 Hz. Additionally, the effect of external load resistance, pushing force, and frequency on the electrical output performance of PNGs was investigated, including its mechanical stability and durability. Finally, an optimized PNG was employed to efficiently harvest/detect the mechanical energy from automotive vehicle motion and human body movements.</P> <P><B>Highlights</B></P> <P> <UL> <LI> BTO was synthesized by a facile, eco-friendly, and cost-effective solid-state reaction. </LI> <LI> Performance of PNG is improved by Ag-NWs and BTO embadded composites. </LI> <LI> Particularly, the risky and high-field poling process was avoided. </LI> <LI> The PNG is employed to effectively harvest the energy from automotive vehicle motions. </LI> <LI> The flexibility of PNG was also examined and used to detect human hand movement. </LI> </UL> </P>