Enhanced Dielectric Response in Poly(Vinylidene Fluoride) ( PVDF ) Ferroelectric Films via Zinc‐Based Metal‐Organic Complex

ABSTRACT To address the urgent demand for high‐energy‐density polymer dielectrics in modern power electronics, this study developed a poly(vinylidene fluoride) (PVDF)‐based nanocomposite dielectric material. A water‐resistant and thermally stable zinc‐based metal‐organic complex (SAZn) was synthesized using 3,5‐di‐tert‐butylsalicylic acid as the ligand and zinc ions as the coordination metal, exhibiting a bandgap of 3.28 eV and dielectric constant of 7.97 (1 kHz). SAZn/PVDF composite films were fabricated via solution casting, with optimized filler‐matrix compatibility to enhance dielectric properties. Research findings: (1) SAZn induces an α → β phase transition in PVDF, elevating β‐phase content from 34.0% to 74.8% at 5 wt% loading and thereby providing high‐density intrinsic dipoles. (2) SAZn significantly reduces the crystallinity of PVDF (52.7% → 30.9% at 5 wt% loading), enhancing polarization by expanding the free volume for dipole movement. This mechanism contrasts fundamentally with conventional coordination polymer/ferroelectric polymer composites. Synergistic interaction of these dual mechanisms yields a maximum dielectric constant ( ε r ) of 19.73 at 1 kHz for the 5 wt% SAZn composite—representing a 79% enhancement over pure PVDF (11.01). Despite a moderate increase in dielectric loss (tan δ = 0.043), the composite demonstrated a discharge energy density ( U e ) of 4.39 J cm −3 and an energy efficiency ( η ) of 53.09% at 500 MV m −1 , surpassing pure PVDF ( U e = 1.74 J cm −3 , η = 47.22%). This study elucidates a novel mechanism of coordination polymers in polymer dielectric composites, providing new insights for the design of high‐energy‐density capacitors.