Ultrahigh energy density and high thermal stability in novel bilayer-structured nanocomposites with surface-decorated TiO2@BaTiO3 nanoparticles

Despite the need to implement renewable energy, it is still hampered by the difficulty of storing and effectively utilizing energy on demand. Herein, for dielectric energy storage application, inaugurally, novel surface-decorated TiO2@BaTiO3 nanoparticles were incorporated in various weight percentage ratios in P(VDF-HFP)-P(VDF) blended polymer and synthesized in new heterogenous bilayer-designed nanocomposite films that contained PEI as its bottom layer. The top layer acted as a polarization layer, the bottom layer operated as an insulation layer, and TiO2@BaTiO3 nanoparticles enhanced polarizability as well as breakdown strength (Eb). The XRD and SEM analysis demonstrated the successful preparation of TiO2@BaTiO3 nanoparticles and bilayer nanocomposite film. Additionally, the ideal bilayer nanocomposite film comparatively demonstrated higher permittivity, lower tangent loss, highest Eb, highest discharge energy density, and optimum charge-discharge efficiency of 11.8, 0.019, 500 MV/m, 14.7 J/cm3, and 76 %, respectively. Also, the TGA analysis revealed enhanced thermal stability by incorporating novel nanoparticles. Moreover, the finite element simulation revealed effective electric field redistribution around TiO2@BaTiO3 nanoparticles and in each layer of bilayer nanocomposites, a mandatory parameter for higher Eb values and energy storage properties. Overall, this work demonstrates that bilayered heterogeneous nanocomposites with TiO2@BaTiO3 surface-decorated nanofillers can be utilized in pulsed power systems and advanced dielectrics.