Ultra high energy density nanocomposite capacitors using surface-functionalized BaTiO 3 nanowires and PVDF-TrFE-CFE

Abstract

High energy density capacitors are critically important in advanced electronic devices and electric power systems due to their reduced weight, size and cost to meet desired applications. Nanocomposites hold strong potential for increased performance, however, the energy density of most nanocomposites is still low compared to commercial capacitors and neat polymers. Here, high energy density nanocomposite capacitors are fabricated using surface-functionalized high aspect ratio barium titanate (BaTiO3) nanowires (NWs) in a poly(vinylidene fluoride-trifluoroethylene-chlorofluoroethylene) (P(VDF-TrFE-CFE)) matrix. These nanocomposites have 63.5% higher dielectric permittivity compared to previous nanocomposites with BaTiO3 nanoparticles and also have high breakdown strength. At a 17.5% volume fraction, the nanocomposites show more than 145.3% increase in energy density above that of the pure P(VDF-TrFE- CFE) polymer (10.48 J/cm3 compared to 7.21 J/cm3). This value is significant and exceeds those reported for the conventional polymer-ceramic composites; it is also more than two times larger than high performance commercial materials. The findings of this research could lead to broad interest due to the potential for fabricating next generation energy storage devices.