Synthesis and characterization of Al-Al2O3/PVDF core-shell nanodieletrics for energy storage

N. Badi, R. Mekala
University of Houston, US

Keywords: nanodielectrics, core-shell nanoparticles, energy storage, embedded capacitors


Extensive interest is being invested into the research of polymer based nanodielectric films. Such a material provides a more practical energy storage solution primarily for embedded capacitors and can be extended for discrete capacitor devices. The highest capacitive density achieved with commercial polymer composite technology is in the order of 10 nF/cm2. Achieving permittivity values K greater than 100 is difficult even with the mature ceramic-filled polymer technology. Experimentally, relative K values of 70 are considered excellent for polymer/ferroelectric composites. We report on a cost effective and innovative method based on creating core-shell nanoparticles in polymer with aluminum (Al) nanoparticles as the high conductivity core and ultrathin aluminum oxide (Al2O3) as capping shell for electrical insulation. The solid oxide shell around the Al core prevents agglomeration of Al nanoparticles. Results shows that proper loadings of thermally oxidized aluminum (Al-Al2O3) in polyvinylidene fluoride (PVDF) polymer provide high permittivity low loss nanodielectrics in par with commercially available capacitor devices along with the added structural flexibility and cost-saving to the end user. The results from TEM/SEM morphology experiments, thermal and frequency response, dielectric strength and dielectric loss of the produced films with different loadings of NPs will be presented.