Enhanced Energy Storage in Nanocomposite Capacitors through Aligned PZT Nanowires by Uniaxial Strain Assembly

The design of nanocomposite capacitors poses certain challenges due to the reduced dielectric strength resulting from the integration of typically high dielectric fillers into the polymer. In prior efforts it was demonstrated that increasing of the filler could lead to energy-storage densities up to 19.3% above the neat polymer. To further enhance the energy density, a novel strategy is developed to align nanowires in a thermoplastic matrix by uniaxial stretching assembly. It is demonstrated that the energy-storage capability of the nanocomposite can be enhanced through the alignment of lead zirconate titanate (PZT) nanowires (NWs) in the direction of the applied electric field compared to randomly oriented samples. The maximum energy density of the nanocomposites is as high as 1.28 J cm-3 at a volume fraction of 40% PZT NWs (aspect ratio around 14) with axis of alignment in the direction of the electric field. The findings of this research could lead to broader interest due to development of the piezoceramic nanocomposites with enhanced dielectric properties for use in next-generation energy-storage and conversion devices.