Polymer-based materials with superb dielectric properties and energy storage performance are of essential significance in today's numerous electronic and electrical power systems. Herein, BaTiO₃ internally decorated hollow porous carbon (BT@HPC) hybrids are prepared via a unique combination of surfactant-free method and sol-gel, which are utilized as the fillers in the two outer layers of a sandwich-structured polymer composite with neat polyvinylidene fluoride (PVDF) as the central layer. Significantly improved permittivity approaches 39 (1 kHz) for the sandwich-structured composite with a low filler content of 7 wt% (~6.02 vol%) attributing to plentiful interfacial space charge polarizations (SCPs) and sophisticated microcapacitor networks constructed by BT@HPCs, while the dielectric loss still retains a low value of 0.03 owing to suppressed carrier transportation by the interfacial obstruction between adjacent layers in this hierarchical architecture. Also, enhanced energy storage density of 10.2 J/cm³ with a high charge-discharge efficiency of 77% is achieved in the sandwich-structured composite with 1 wt% (~0.85 vol%) BT@HPC under a relative low applied electric field of 360 MV/m, to which interfacial barrier effect and redistribution of local electric field in the multilayer configuration make vital contributions. This work broadens the avenue to reinforce performance of polymer dielectrics for capacitive energy storage applications by designing specific structured particles as fillers in hierarchical architecture composite.

在当今众多的电子和电力系统中，具有出色介电性能和能量存储性能的聚合物基材料至关重要。在此，BaTiO ₃内部装饰的中空多孔碳（BT @ HPC）杂化物是通过无表面活性剂方法和溶胶-凝胶的独特组合制备的，它们被用作具有纯聚偏二氟乙烯的三明治结构聚合物复合材料的两个外层的填料（ PVDF）作为中心层。夹层结构复合材料的低介电常数接近39（1 kHz），填充剂含量低至7 wt％（〜6.02 vol％），归因于BT @ HPC构成的大量界面空间电荷极化（SCP）和复杂的微电容器网络，在这种分层体系结构中，由于相邻层之间的界面阻塞抑制了载流子传输，介电损耗仍保持0.03的低值。此外，能量存储密度提高了10.2 J / cm ³在360 MV / m的相对较低施加电场下，具有1 wt％（〜0.85 vol％）BT @ HPC的夹心结构复合材料可实现77％的高充放电效率多层结构中局部电场的重新分布做出了至关重要的贡献。这项工作通过将特定的结构化颗粒设计为分层结构复合材料中的填料，从而拓宽了增强聚合物电介质在电容式能量存储应用中性能的途径。