| Summary: | This work provided an alternative route to balance the significantly increased dielectric permittivity (ε′) and effectively retained tanδ using an effective two-step concept. Ag-deposited nano-sized BaTiO<sub>3</sub> (Ag-<i>n</i>BT) hybrid particle was used as the first filler to increase the ε′ of the poly(vinylidene-fluoride) (PVDF) polymer via the strong interfacial polarization and a high permittivity of <i>n</i>BT and suppress the increased loss tangent (tanδ) owing to the discrete growth of Ag nanoparticles on the surface of <i>n</i>BT, preventing a continuous percolating path. The ε′ and tanδ values at 10<sup>3</sup> Hz of the Ag-<i>n</i>BT/PVDF composite with <i>f</i><sub>Ag-<i>n</i>BT</sub>~0.29 were 61.7 and 0.036. The sub-micron-sized BaTiO<sub>3</sub> (<i>μ</i>BT) particle was selected as the blocking particles to doubly reduce the tanδ with simultaneously enhanced ε′ due to the presence of the tetragonal BT phase. The <i>μ</i>BT blocking particles can effectively further inhibit the formation of conducting network and hence further reducing tanδ. By incorporation of <i>μ</i>BT clocking particles with <i>f<sub>μ</sub></i><sub>BT</sub> = 0.2, the ε′ value of the Ag-<i>n</i>BT/PVDF-<i>μ</i>BT composite (<i>f</i><sub>Ag-<i>n</i>BT</sub> = 0.30) can significantly increase to 161.4, while the tanδ was reduced to 0.026. Furthermore, the tanδ was lower than 0.09 in the temperature range of −60–150 °C due to the blocking effect of <i>μ</i>BT particles.
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