Modulation of topological structure induces ultrahigh energy density of graphene/Ba0.6Sr0.4TiO3 nanofiber/polymer nanocomposites
Modulation of topological structure induces ultrahigh energy density of graphene/Ba0.6Sr0.4TiO3 nanofiber/polymer nanocomposites
复制标题
拓扑结构调控诱导石墨烯/Ba0.6Sr0.4TiO3纳米纤维/聚合物纳米复合材料超高能量密度
DOI：
10.1016/j.nanoen.2015.10.003
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发表时间：
2015-11-01
期刊：
影响因子：
17.6
通讯作者：
Nan, Ce-Wen
中科院分区：
文献类型：
--
作者：
Shen, Yang;Hu, Yuhan;Nan, Ce-Wen
介质电容器由于具有超快充放电和超高功率密度的特性，已成为先进电子和电力系统中许多应用的主要推动者。为了减小介电电容器的尺寸和成本，高能量密度的介电材料是非常可取的，这对于电脉冲电源系统和电动汽车中的电力电子设备至关重要。聚合物纳米复合材料有望提高目前使用的纯聚合物电介质的低能量密度。本研究采用简易热压法制备了一类三明治结构的纳米复合材料。聚偏氟乙烯纳米复合材料层填充氧化石墨烯纳米片，涂覆二氧化钛纳米粒子（g层）或Ba0.6Sr0.4TiO3纳米纤维（b层），从溶液中铸造并组装成具有反向拓扑结构的三明治结构纳米复合材料（BGB a GBG）。在BGB纳米复合材料中实现了14.6 J/cm(3)的超高能量密度。相场模拟揭示了拓扑结构对纳米复合材料介电性能的重要影响。通过合理设计拓扑结构和各层的介电性能，可以使夹层结构纳米复合材料各组成层之间的局部电场分布良好，从而提高材料的电极化和介电击穿强度，从而获得超高的能量密度。(C) 2015 Elsevier Ltd.版权所有。
Dielectric capacitors have been the major enabler for a number of applications in advanced electronic and electrical power systems due to their capability of ultrafast charging-discharging and ultrahigh power density. High energy density dielectrics are highly desirable in order to reduce the size and cost of dielectric capacitors, which is critical for electrical pulse-power systems and power electronics in electric vehicles. Polymer nanocomposites are promising in raising the low energy density of neat polymer dielectrics of current use. In this study, a class of sandwich-structured nanocomposites are prepared by a facile hot-pressing method. Polyvinylidene fluoride nanomcomposite layers filled with graphene oxide nanosheets coated with TiO2 nanoparticles (G-layers) or Ba0.6Sr0.4TiO3 nanofibers (B-layers) are cast from solution and assembled into sandwich-structured nanocomposites with reversed topological strcuture (BGB a GBG). An ultrahigh energy density of 14.6 J/cm(3) is achieved in the BGB nanocomposites. Phase-field simulations reveal the significant implications of topological structure on the dielectric performance of the nanocomposites. By rational design of topological structure and the dielectric property of the individual layers, favorable distribution of local electrical field could be achieved among the constituent layers of the sandwich-structured nanocomposites, giving rise to the concomitant enhancement of electrical polarization and dielectric breakdown strength, and hence ultrahigh energy density. (C) 2015 Elsevier Ltd. All rights reserved.