Energy Density Limits of Multiphase Composites With Dielectric Nanoparticles

Analyzing electric field distributions of multiphase nanoparticle (NP) composites can provide physical insight into their energy density limits. A three-dimensional simulation platform that uses a control volume approach with a finite difference grid is created to efficiently calculate electric field patterns, effective permittivity, and energy density of multiphase composites. To estimate a maximum energy density metric for materials, a physically based percolation model is used to estimate the maximum voltage that can be applied to materials before a potential breakdown path occurs. The simulation predictions are compared to measured data from current work on BaTiO3 NPs infused in a PVDF matrix to help verify simulation results. The simulation platform is then used to explore the possible energy density limits for a variety of nanocomposite material configurations. For example, one such nanocomposite category that is highlighted is the one in which certain metal-oxide dielectric NPs can have localized and highly polarizable dipoles at their surfaces. Finally, simulation is used to explore the impact that an NP's average diameter, degree of clustering, and volumetric density can have on the maximum energy density for a variety of nanocomposite material types.