Dielectric properties and discharged energy density of poly(vinylidene fluoride) composites with dopamine-modified PMN-PT particles

Dielectric composites have been witnessed a surge of interest in the past few years for its potential application in energy storage due to their excellent dielectric properties and superior breakdown strength. In this work, PMN-PT particles were modified by dopamine and were used to prepare PMN-PT@Dopa /polyvinylidene fluoride (PVDF) composites. The maximum dielectric constant (ε_r) of composites with PMN-PT particles was 19.25 (1 kHz). The dielectric loss (tanδ) of composites with different volume fraction of PMN-PT was all below 0.03. The discharged energy density (U_dis) of composites with 3 vol% PMN-PT@Dopa particles reached 11.07 J/cm³ at 370 kV/mm. The energy efficiency (η) of composites remained 40% at 350 kV/mm. The composite with PMN-PT@Dopa particles exhibited good fatigue endurance after 10⁶ cycles. The results demonstrated that composites with PMN-PT particles possessed potential application in dielectric property and energy storage.