▎ 摘　　要

A variety of multi-layer nanocomposite films composed of both high insulation polyimide(PI)layer and high dielectric constant graphene oxide/polyimide (GO@PI) composite layer were fabricated through layer by layer coating. The GO content and layered structure of the dielectric layer were adjusted to make the multi. layer composite films with high dielectric constant and high breakdown strength. The results showed that the energy storage density of tri-layer PI/1.0 GO@PI/PI composite film was 1.27 J/cm(3) at 261.5 kV/mm. Compared with the mono-layer 1.0 GO@PI film, the breakdown strength and energy storage density of the tri-layer PI/1.0 GO@PI/PI composite film were increased by 97% and 144%, respectively. Meanwhile,the dielectric loss of the composite film remained at a relatively low level (tan delta=0.0079). The composition of insulating layer and high dielectric layer afforded the synergistic effect to remedy the energy density of the multilayer composite film. The multi-layer structure strategy is benefical to the application of graphene oxide/polyimide composites in dielectric energy storage filed.