At high temperatures and strong electric fields

the excitation and transfer rates of electrons in dielectrics accelerate

leading to a sharp increase in conduction losses

which severely affects the energy storage performance and application of dielectrics. This study utilizes 2

4

6—triaminopyrimidine (TAP) as a cross-linking agent to prepare cross-linked polyimide (PI/TATP) composite films. Through performance testing and simulation

the research investigates the impact of the cross-linked effect on the electron migration and energy storage performance of the composite films. Research results indicate that the cross-linked network structure can reduce the free volume between molecular chains and inhibit the transport of charge carriers. The introduction of a wide bandgap TAP crosslinking agent establishes an additional energy barrier between the PI (polyimide) and TAP

which suppresses electron transitions and effectively reduces the conduction loss in the dielectric film. When the content of the cross-linking agent is 1%

the energy density of the PI/TATP composite dielectric reaches 4.41 J/cm3 at 150℃ and 578 MV/m

while the charge-discharge efficiency remains above 90%

representing a 79.3% improvement over the original PI film. This research provides theoretical and technical references for the development of high- performance capacitors.