| Combining their respective advantages of ceramic and polymer dielectric, polymer-based ceramic composites which are used as energy-storage materials have extensive application prospect. In this paper, nickel/barium titanate/polyvinydene fluoride (Ni/BaTiO3/PVDF) composites were prepared by physical blending method, The relationship between dielectric property,breakdown strength,energy storage density and content of modified Ni,BaTiO3 were studied. In addition, laminated BaTiO3/PVDF composites were prepared via spin coating technique and tape casting process respectively, and the effect of laminated structure on the dielectric property were discussed systemically.1) The dielectric constant of Ni/BaTiO3/PVDF composites increased with increasing BaTiO3 content and showed an earlier raise and later decreased as Ni content increasing, the composites containing 1w% Ni provided optimal dielectric constant of 40 (50v% BaTiO3). The breakdown strength showed down trend with increasing BaTiO3 content and also showed an earlier raise and later decreased as Ni content increasing, The breakdown strength stayed above 175Kv/mm when Ni content was 3w%, which can be explained via Coulomb blockade effec. Energy storage density containing 3w% Ni can keep at high levels, more than 2.0 J/cm3.2) Clear interfaces without scaling were formed in laminated BaTiO3/PVDF composites prepared using spin coating and tape casting process. The laminated BaTiO3/PVDF composites exhibited larger enhancement of low frequency dielectric constant. In the double-layer composites, dielectric constant can reach 190 when BaTiO3 content is 55v%, in which dielectric constant is three times larger than that of single PVDF/BaTiO3 composites, the result may be attributed to Maxwell-Wagner interfacial polarization. The breakdown strengths of laminated BaTiO3/PVDF composites remained below 10 Kv/mm due to space charge traped at interlayer interface, which were far lower than that of single composites. |
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