Core@Double–Shell Engineering of Zn Particles toward Elevated Dielectric Properties: Multiple Polarization Mechanisms in Zn@Znch@PS/PVDF Composites

Abstract Flexible dielectrics with large dielectric constant ( ε ′) coupled with low loss are highly pursued in many applications. To bolster the ε ′ of raw Zn (zinc)/poly(vinylidene fluoride, PVDF) while maintaining pimping dielectric loss, in this study, the core@double–shell structured Zn@zinc carbonate (ZnCH)@polystyrene (PS) particles are first synthesized through a suspension polymerization of styrene, and then composited with PVDF to elevate the ε ′ and keep low loss of the composites. By optimizing the PS shells’ thickness and tailoring the electrical resistivity of Zn@ZnCH@PS particles, both the slow inter‐particle polarization and fast intra‐particle polarization in the composites can be decoupled and synergistically tuned, thus, the Zn@ZnCH@PS/PVDF achieves a much higher ε ′ and lower dielectric loss, simultaneously, which far exceed the unmodified Zn/PVDF. Both experiment and theoretic calculation reveal that the double‐shell ZnCH@PS not only induces and promotes multiple polarizations enhancing the composites’ ε ′, especially at the optimized PS's thickness, but also maintains suppressed loss and conductivity thanks to their obvious barrier effect on long‐range charge migration. The core@double–shell filler design strategy facilitates the development of polymer composites with desirable dielectric properties for applications in electronic and electrical power systems.