The Experts below are selected from a list of 8532 Experts worldwide ranked by ideXlab platform

Hong Wang - One of the best experts on this subject based on the ideXlab platform.

Jiwei Zhai - One of the best experts on this subject based on the ideXlab platform.

  • discharged energy density and efficiency of nanocomposites based on poly vinylidene fluoride and core shell structured batio3 al2o3 nanoparticles
    Ceramics International, 2018
    Co-Authors: Jiao Wang, Limin Zhao, Jiwei Zhai
    Abstract:

    Abstract High discharged energy density and efficiency composites dielectric capacitors have gained world-wide attention. We apply a solution casting method to prepare films of PVDF nanocomposites containing sol-gel processed core-shell structured BaTiO 3 @Al 2 O 3 nanoparticles. Their Interfacial Polarization and discharged energy density performance were investigated. On the morphological characterizations, the core-shell nanoparticles based on TEM were found to have Al 2 O 3 with an average thickness of 6 nm, which acts as a shell layer coating on the surface of the BaTiO 3 -core. SEM results indicate that the core-shell nanoparticles created are dispersed uniformly in the PVDF matrix. Among the studied PVDF nanocomposites with different BaTiO 3 @Al 2 O 3 nanoparticle loadings, the nanocomposite with 5 vol% BaTiO 3 @Al 2 O 3 nanoparticles shows the highest discharged energy density of 6.1 J/cm 3 , which is 1.2 times higher than that of the nanocomposite with pure BaTiO 3 nanoparticles. For the 5 vol% of BaTiO 3 @Al 2 O 3 nanoparticles added, the resulting nanocomposite exhibits a high efficiency of 81.6% below 1000 kV/cm and is higher than 66.5% at 2800 kV/cm. The enhanced discharged energy density and efficiency could be attributed to the improvement of the Maxwell-Wagner-Sillars Interfacial Polarization at the dynamic interface between PVDF matrix and BaTiO 3 @Al 2 O 3 nanoparticles by which the difference of dielectric constant at the interface is reduced.

  • correlation of energy conversion efficiency and interface Polarization in niobate glass ceramic for energy storage applications
    Applied Physics Letters, 2015
    Co-Authors: Wenqin Zhang, Bo Shen, Jiwei Zhai
    Abstract:

    The correlation between energy conversion efficiency and interface Polarization was investigated according to the discharge performance and impedance spectroscopy as a function of annealing temperatures in BaO–Na2O–Nb2O5–SiO2 glass ceramic system. The experiment results show that the energy conversion efficiency strongly depends on the interface Polarization. The annealing temperature dependence of the energy conversion efficiency is attributed to the variation of Interfacial Polarization, according to the results of complex impedance analysis.

Dou Zhang - One of the best experts on this subject based on the ideXlab platform.

  • suppressed Polarization by epitaxial growth of srtio3 on batio3 nanoparticles for high discharged energy density and efficiency nanocomposites
    Nanoscale, 2020
    Co-Authors: Xuefan Zhou, Feng Dang, Kechao Zhou, Dou Zhang
    Abstract:

    In order to meet the increasing demand of integration and miniaturization of electronic components, capacitors with high energy density are urgently needed. In this work, a strategy of suppressing Interfacial Polarization for obtaining enhanced energy density and efficiency polymer based nanocomposites is proposed. This strategy is conducted by epitaxial growth of a SrTiO3 layer with a moderate dielectric constant on the surface of a BaTiO3 core to form a kind of novel filler and compositing with the P(VDF-HFP) matrix to prepare dielectric nanocomposites. The SrTiO3 shell could effectively confine the mobility of charge carriers to enhance the dielectric strength of the composites and improve the energy efficiency by reducing the Maxwell–Wagner–Sillars (MWS) Interfacial Polarization and space charge Polarization between the BaTiO3@SrTiO3 fillers and the P(VDF-HFP) matrix due to their similar crystal structure and lattice parameter. The nanocomposite containing 1 vol% BaTiO3@SrTiO3 nanoparticles achieved a discharged energy density of 13.89 J cm−3 and an energy efficiency of 63% at 494.7 kV mm−1, which are superior to 9.96 J cm−3 and 50% of BaTiO3/P(VDF-HFP) nanocomposites with the same loading, respectively, and its discharged energy density is 69% higher than 8.2 J cm−3 of the neat P(VDF-HFP) at 401.5 kV mm−1. This work provides an effective way for nanocomposite capacitors with high energy density and efficiency.

  • enhanced energy density in p vdf hfp nanocomposites with gradient dielectric fillers and Interfacial Polarization
    Journal of Alloys and Compounds, 2017
    Co-Authors: Qiao Huang, Xuefan Zhou, Kechao Zhou, Chao Chen, Dou Zhang
    Abstract:

    Abstract Dielectric capacitors are of urgently demand in modern micro-electric industry. The surface modified inorganic filler introduced to polymer matrix represents a promising avenue for the dielectric material's enhancement of energy storage density. To ease the electric field concentration of the composite induced by permittivity difference between ceramic fillers and polymer matrix, the specific dielectric fillers of TiO 2 nanowires modified BT particles were synthesized in this study. Gradient dielectric composite consisting of poly(vinylidene fluoride-co-hexafluoropylene) [P(VDF-HFP)] matrix ( e r ∼10), TiO 2 shell ( e r ∼40), and BaTiO 3 (BT) core ( e r ∼1000) were focused to investigate the electric field contribution and interface Polarization. The results revealed that the permittivity of the composites increased as a result of large Interfacial Polarization induced by the large specific surface area of the nanowires as compared to the composite with randomly mixed TiO 2 /BT fillers. The breakdown strength of the composite was slightly improved with 20 vol% fillers, attributed to the fact that the electric field intensification was weakened by the BT@TiO 2 /Dop gradient dielectric fillers. The composite could endure up to 10 6 times of field cycling at the applied cycling field and the leakage current density was rather low. The composites with 20 vol% fillers exhibited a discharged energy density of 2.8 J/cm 3 at a low electric field, which was much higher than that of the neat P(VDF-HFP). The findings of this research introduced a new inorganic particle with large specific surface area and gradient dielectric permittivity as filler in composite for energy storage application.

Yujuan Niu - One of the best experts on this subject based on the ideXlab platform.

Yongcun Zhou - One of the best experts on this subject based on the ideXlab platform.