Polypropylene (PP) is widely used in film capacitors but is limited by an intrinsic trade-off between dielectric permittivity and breakdown strength, capping energy density around 3 J cm- 3. This limitation is overcome by introducing a liquid silicone rubber (LSR107) interphase and BaTiO3 (BT, diameter 5 nm) nanofiller into PP via one-step melt extrusion, creating a ternary nanocomposite with a hierarchical interphase-regulated structure. LSR107 selectively local