Energy storage property of ZIF-8/polypropylene nanocomposites

Polypropylene (PP), while dominantly employed in film capacitor applications, faces critical limitations due to its intrinsic low energy density. This work demonstrates a breakthrough strategy through interfacial engineering with zeolitic imidazolate framework-8 (ZIF-8). The hierarchical pore architecture of ZIF-8 effectively confines space charge migration, suppressing electron avalanche ionization. Melt blending fabricated ZIF-8/PP nanocomposites with ultralow loadings (0.2-0.4 wt.%) exhibit simultaneously enhanced dielectric permittivity ([Formula: see text] [Formula: see text] 2.24 at 0.2 wt.%, 2.04 for pure PP at 100 Hz) and breakdown strength (342.98 kV/mm at 0.4 wt.%, 48.7% improvement over pristine PP). Remarkably, the dielectric loss tangent plunges to 3.24 × 10[Formula: see text], outperforming most reported PP-based composites. The optimal composite achieves an energy density of 1.25 J/cm 3 , representing a 130% enhancement versus baseline PP. This nanoconfinement engineering approach maintains industrial process compatibility, paving the way for next-generation high-power capacitors.