▎ 摘　　要

Although a polymer film capacitor releases a huge power density in pulse time, its electrical capability is limited by the low energy density for the embedded hybrid device. It is still a challenge to increase the energy density and retain high charge-discharge efficiency of the polymer film. High dielectric properties and high energy density are obtained in the uniaxial stretching poly(vinylidene fluoride-chlorotrifluoroethylene) (P(VDF-CTFE)) nanocomposite incorporated with few-layer graphene, which is exfoliated with the assistance of a fluoro hyperbranched polyethylene-graft-poly(trifluoroethyl methacrylate) (HBPE-g-PTFEMA) copolymer via CH-pi noncovalent interactions. The graphene/P(VDF-CTFE) nanocomposite film is prepared via solution casting, and then, the in-plane orientation of nanosheets is accomplished by uniaxial deformation. The relative content of the beta phase reaches 96.0% in 0.8 vol% nanocomposite due to the combination of improved compatibility and the alignment of macromolecular chains. The energy density of a 0.1 vol% graphene/P(VDF-CTFE) film achieves 9.5 J cm(-3) as E = 400 MV m(-1), which is attributed to the large-content electroactive phase and interfacial polarization. The P(VDF-CTFE) nanocomposite incorporated with aligned graphene exhibits a promising energy storage capability, which indicates that the orientation of nanosheets is an effective solution to enhance the energy density of the polymer film with large charge-discharge efficiency.