High-temperature dielectric polymers with high breakdown strength and energy density via constructing the electron traps in blends

The n-type semiconductive polymer with perylene diimide (PTCBI) filler can immobilize electrons to reduce charge transport in the blends. In this paper, the influence of PTCBI loading on the dielectric and energy storage performances of PTCBI/PEI blends was studied. The results showed that the highest dielectric constant of 7 at 1 KHz was found in 4 wt% PTCBI/PEI blends. Importantly, PTCBI/PEI blends presented excellent temperature stability of dielectric properties from 25 ℃ to 150 ℃. The breakdown strength of PTCBI/PEI blends improved from 359 kV/mm to 485 kV/mm when the increased content of PTCBI filler was below 1 wt%. The η of 86% and the maximal discharge energy density (Ud) of 8.0 J/cm3 were achieved at 540 kV/mm in 1 wt% PTCBI/PEI blends. Meanwhile, the η of 82% and the Ud of 5.12 J/cm3 at 500 kV/mm at 100 ℃ was obtained.