Functionalized carbon nanotubes/polyimide nanocomposites with high energy density for high-temperature dielectric materials

Polymer-based dielectric capacitors have attracted much attention because of their good flexibility, lightness, and high-power density. However, the current polymer dielectric capacitors usually have too low energy density and cannot be used in high temperature environments, which limits the further development. Therefore, it has become increasingly important to develop high-temperature dielectric materials with high energy density and low dielectric loss. In this study, long-chain functionalized carbon nanotubes (CNTF) were introduced in Polyimide (PI) to obtained CNTF/PI composite film. CNTF have good compatibility with polymer and can solve the dispersion problem. The CNTF/PI composite film exhibits good dielectric property and an ultralow dielectric loss of 0.015. Especially, the discharged energy density of 3.77 J/cm(3) of CNTF/PI composite film is the highest discharged energy density of reported polyimide-based dielectric films at 300 MV/m. Therefore, these polyimide-based dielectric materials are promising in the high temperature field of novel high-performance film dielectric capacitor.