Defect-assisted grafted nanosieves interfacial coupling and adjacent space electric field modulation in poly(vinylidene fluoride)

Poly(vinylidene fluoride) (PVDF), the most extensively studied ferroelectric polymer, is a competitive candidate for use in the next-generation energy storage and smart interactive fields. However, the widely strategy of using copolymers to reduce the coercive field at the cost of a lower breakdown strength and high expenses. Here, we graft bipolar sodium dodecylbenzene sulfonate onto Co₃O₄ nanosieves (NSs@SDBS) with abundant surface defects and introduce this nanomaterial into PVDF at a low doping quantity. The adjacent spatial electric field (E) regulation effect of 2D nanosieves is revealed, reducing electric field distortion by half, achieving a 50 % increase in the DC breakdown strength (E_b) while reducing the coercive field (E_c) of PVDF by 28 %. Furthermore, the strong coupling effect of SDBS between PVDF and nanosieves is beneficial to optimize the interface crystalline phases configuration and eliminate pinholes, thereby improving the uniformity and integrity of the films. The energy storage density of P-NSs@SDBS-L₂ is 2.1 times that of pure film, and the efficiency is increased by 12.5 %. This dual-function modification strategy for E_b and E_c is generally applicable to nanodielectrics, ferroelectric materials and other related applications.