Study On Dielectric Properties And Energy Storage Density Of BZT/PVDF Composites

Composite systems of ceramics and polymers have attracted increasing attention because they have the potential to improve energy density by improving dielectric constant and breakdown field strength at the same time.BaZr_0.1Ti_0.9O₃?BZT?ceramic powders were prepared by solid-state method,and were compounded with polyvinylidene fluoride?PVDF?,and BZT/PVDF composite films were prepared by tape casting method.The surface of BZT particles was modified by silane coupling agent KH550,and the optimum proportion of BZT ceramics and PVDF polymers was explored.BZT ceramic fillers were doped with Nd³⁺and PVDF matrix was modified with conductive polyaniline?PANI?to obtain excellent composite materials.The experimental results show that:The filling volume of BZT ceramic particles will significantly affect the dielectric properties of BZT/PVDF composites.A suitable amount of silane coupling agent KH550can obviously improve the dispersion of BZT filler in PVDF polymer and improve the material properties.BZT ceramics filled with 40 vol%,silane coupling agent KH550 used for 1 wt%,the optimum dielectric constant 51,dielectric loss 0.58,theoretical energy storage density 0.863 J/cm³ under 44 kV/cm electric field,discharge efficiency 49.55%.When the Nd³⁺doping amount is 0.6 mol%,the dielectric constant of BZT ceramics is4384 and the dielectric loss is 0.0068.The dielectric properties of Nd³⁺doped BZT/PVDF composites show similar changes to BZT ceramics.The dielectric constant and dielectric loss of Nd³⁺doped BZT/PVDF composites reach 62 and 0.046 respectively when the doping is 0.6 mol%.The maximum theoretical energy storage density is 1.41 J/cm³ and the discharge efficiency is 55.06%under 44 kV/cm electric field.The addition of PANI enhances the crystallization of the beta phase of PVDF,and remarkably enhances the dielectric constant and dielectric loss of the composites.The dielectric properties of BZT/PVDF composites doped with 6 vol%PANI are the best,with a dielectric constant of 69 and a dielectric loss of 0.057.When the PANI doping amount is8 vol%.The theoretical energy storage density of the composite material is 1.54 J/cm³,and the discharge efficiency is 54.17%at 40 kV/cm electric field.Figure 37;Table 6;Reference 59.