ABSTRACT The rapid evolution of pulsed‐power systems and microelectronic modules, which are demanding ever‐higher energy‐storage densities, has intensified the search for polymer dielectrics that can deliver both high discharged energy density ( U d ) and robust charge–discharge efficiency ( η ). To address the low energy storage density of polyetherimide (PEI). Two‐dimensional montmorillonite nanosheets were synthesized by the liquid‐phase intercalation method in this study. Herein, organophilic montmorillonite (OMMT) nanosheets were homogeneously dispersed in polyetherimide (PEI) via solution casting. At only 0.5 wt% OMMT, the resultant film exhibits a relative permittivity of 4.20 while maintaining an ultralow dielectric loss (tan δ < 0.015) across 10 2 –10 5 Hz. Weibull statistics yield a characteristic breakdown strength of 542.98 MV/m, corresponding to a 36.5% increase over neat PEI, and deliver a discharge energy density of 5.68 J cm −3 ‐an enhancement of 95.9% with charge–discharge efficiency remaining above 80.0%. Finite‐element simulations (COMSOL) reveal that the OMMT layers establish an electrostatic shield that impedes electrical‐tree propagation, rationalizing the superior breakdown endurance. These results underscore the high‐temperature potential of OMMT/PEI nanocomposites for next‐generation dielectric capacitors.
Liu et al. (Thu,) studied this question.