High energy density of ferroelectric polymer nanocomposites utilizing PZT@SiO2 nanocubes with morphotropic phase boundary

Polymer-based nanocomposites embedded high dielectric-constant (high- ε r ) ceramic fillers in high breakdown-strength (high- E b ) polymer matrix are extensively studied as the flexible dielectrics for high discharged-energy–density (high- U e ) film capacitors. Ferroelectric ceramics composition lying on the morphotropic phase boundary (MPB) show ultrahigh dielectric and polarization response, which as ceramic fillers, have great promise to enhance the U e of polymer/ceramic composites. Herein, high- ε r Pb(Zr 0.52 Ti 0.48 )O 3 (PZT) nanocubes (NCs) with MPB composition are prepared successfully via an improved hydrothermal reaction. Based on this, core–shell structured PZT@SiO 2 nanofillers are designed to reduce the uneven electric field distribution and leakage current in P(VDF-CTFE)-based nanocomposites for high E b . We demonstrate that the PZT@SiO 2 nanofillers with MPB composition can effectively resolve the paradox between ε r and E b . The prepared P(VDF-CTFE)/PZT@SiO 2 nanocomposites can display a high U e of 16.8 J/cm 3 at E b of 491 MV/m, which is substantially improved by 107% over the pristine P(VDF-CTFE). Plus, high discharging efficiency of 70% is also achieved. The superiority of the PZT@SiO 2 NCs with MPB in improving the capacitive energy density of film capacitors will be expected to provide a design paradigm for advanced polymer composites with high energy storage performance.