Engineering High-Performance Dielectric Thin Films from Poly(methyl methacrylate) (PMMA)/Metal–Organic Complex Hybrid

To address the urgent demand for high-energy-density polymeric dielectrics in electrostatic capacitors, researchers synthesized a zinc-based compound (SAZn) as a dielectric filler. Incorporating it into a poly(methyl methacrylate) (PMMA) matrix yielded SAZn/PMMA composite films. At low doping levels, SAZn effectively modulates the microstructure of the PMMA matrix: its incorporation increases the interchain spacing of PMMA, lowers the glass transition temperature, and elevates the Young’s modulus of the composite film to 1.63 GPa. The dielectric constant of the 4%-SAZn/PMMA composite film at 1 kHz is 14.1, which is 2.9 times that of pure PMMA. Meanwhile, the 4%-SAZn/PMMA composite film exhibits a discharged energy density of 6.14 J/cm3 and a discharge efficiency of 88.2%, which are 1.53 and 1.45 times those of pure PMMA, respectively. This study provides a viable strategy for designing high-energy-density, fully organic dielectric energy storage films.