Ultrafine core-shell BaTiO3@SiO2 structures for nanocomposite capacitors with high energy density
Ultrafine core-shell BaTiO3@SiO2 structures for nanocomposite capacitors with high energy density
复制标题
用于高能量密度纳米复合电容器的超细核壳BaTiO3@SiO2结构
DOI：
10.1016/j.nanoen.2018.07.006
复制
发表时间：
2018-09-01
期刊：
影响因子：
17.6
通讯作者：
Huang, Yunhui
中科院分区：
文献类型：
--
作者：
Bi, Ke;Bi, Meihua;Huang, Yunhui
介质电容器是脉冲功率系统中不可替代的储能元件，但现有材料体系的低能量密度限制了其小型化和进一步应用。在本工作中，利用直径小于10 nm的核壳BaTiO_3@SiO_2(BT@SO)结构制备了一种新型聚合物/陶瓷纳米复合材料。这种超细纳米结构不仅提供了高绝缘的SiO_2层，以优化常规的核-壳结构的微观结构和介电响应，而且具有比传统的100 nm填料大近10倍的界面，实现了高极化，可以有效地同时提高复合材料的击穿强度和电位移。BT@SO/PVDF纳米复合材料具有简单、通用的0-3型结构，其中0维纳米粒子嵌入到三维连接的聚合物基质中，在420kV/mm时表现出优异的储能性能，Umax=11.5J/cm(3)。实验结果和相场模拟均证实了超细纳米结构在提高介电纳米复合材料能量密度方面的优越性，为高能量密度复合材料的设计提供了新的技术途径。
Dielectric capacitors are irreplaceable energy-storage components in pulsed power systems, but the low energy density (Ue) of existing material systems restricts their miniaturization and further application. In this work, a novel polymer/ceramic nanocomposite is fabricated using core-shell BaTiO3@SiO2 (BT@SO) structures with a diameter less than 10 nm. Such ultrafine nanostructure not only provides a high insulating SiO2 layer to optimize the microstructure and dielectric response as normal core-shell structures, but also has almost tenfold larger interfaces than conventional 100 nm fillers to realize a high polarization, which can effectively improve the breakdown strength as well as the electrical displacement of the composite simultaneously. With a simple and universal 0-3 type structure, in which 0-dimentional nanoparticles are embedded in a 3-dimentional connected polymer matrix, the BT@SO/PVDF nanocomposite shows outstanding energy storage performance with Umax = 11.5 J/cm(3) at 420 kV/mm. Experimental result and phase field simulation both confirm the superiority of the ultrafine nanostructures in enhancing the energy density of the dielectric nanocomposite, providing a new technological way for the design of high energy-density composites.