| With the rapid development of electronic technology industry,there is increasing need for capacitors with smaller size,large capacity and flexibility.Meanwhile,capacitors with high power and energy density are of vital importance for it accounts for very large portion of pulse apparatus.In both aspacts of renewable resources and military,those high power capacitors are considered as promising dielectrics for their exceptional properties.From the respect of irregular inclusions,especially two-dimensional fillers,low addition of fillers is expected to prepare polymer-based dielectric nanocomposites with low dielectric loss,high dielectric strength and high-energy storage.Natural vermiculite and Zirconia are chosen as raw materials,and with proper treatment,the 2D inclusion with large aspect ratio are prepared.Further fabricating with polymer matrix PVDF made nanocomposites with excellent dielectric properties.Only 5wt% loading of vermiculite nanosheets effectively reduces the remnant polarization and futher increases the breakdown strength at 428 k V/mm.Such nanosheets with high aspect ratio effectively decreases the content of fillers for dielectric nanocomposites.Meanwhile the orientation of fillers in such a fashion that are perpendicular to the electric field makes the composites more difficult to breakdown,for its conduction path becomes more tortuous.As nucleation agent during recrystallization,those filler reduces crystalline size leading to smaller ferroelectric domain,which favors the reversal of the magnetic domains,thus lower Pr.On the other hand,the 1wt% ZrO2/PVDF nanocomposites enhanced the insulating and mechanical properties of polymer matrix,leading to exceptional dielectric properties.Specifically,the breakdown strength increases from 416 k V/mm for pristine PVDF to 519 k V/mm,the energy density increases from 8.18 J/cm3 to 11.03 J/cm3,which is promising dielectrics to be used in the high power capacitors. |
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