Liu Shuhang, Xu Xin, Peng Mingyu, Guo Yiting, Xu Jie, Gao Feng
State Key Laboratory of Solidification Processing, MIIT Key Laboratory of Radiation Detection Materials and Devices, USI Institute of Intelligence Materials and Structure, School of Materials Science and Engineering, Northwestern Polytechnical University, Xi'an 710072, Shaanxi, P. R. China.
Department of Orthopedic Trauma, Honghui Hospital of Xi'an Jiaotong University, Xi'an 710054, China.
ACS Appl Mater Interfaces. 2024 Nov 6;16(44):60948-60957. doi: 10.1021/acsami.4c11672. Epub 2024 Oct 25.
BaSrTiO/polyvinylidene fluoride (BST/PVDF) dielectric functional composites have been widely used in flexible wearable devices, capacitors, and energy storage devices. In addition to the ceramic phase type, polymer matrix type, composition, and interfacial connectivity of BST/PVDF composite materials, their morphology also significantly influences their electrical characteristics. Therefore, herein, sandwich-structured BST/PVDF layered composites were designed and prepared via tape-casting processing using different types of BST fillers [i.e., formless zero-dimensional (0D)-BST, rod-like one-dimensional (1D)-BST, and plate-like two-dimensional (2D)-BST]. The microstructures and electrical characteristics of sandwich-structured BST/PVDF composites were studied in relation to the BST morphology. The effects of the internal mechanisms of different interfacial models on the breakdown strength of BST/PVDF composites were discussed. According to our findings, unlike the 0D-BST and 1D-BST powders, 2D-BST powders form multiscale parallel interfaces in sandwich-structured composites due to their unique lamella-like morphology, which enhances the breakdown strength of sandwich-structured composites. Sandwich-structured BST/PVDF composites containing 2D-BST powders exhibit good electrical characteristics with an energy storage density of 19.71 J/cm, an energy storage efficiency of 85.3%, a dielectric constant of 30.4 (1 kHz), a dielectric loss of 0.036 (1 kHz), and a dielectric tunability of 93.2%. This study provides a method for preparing functional composites with high dielectric tunability and high energy storage characteristics.
钛酸钡锶/聚偏氟乙烯（BST/PVDF）介电功能复合材料已广泛应用于柔性可穿戴设备、电容器和储能设备。除了BST/PVDF复合材料的陶瓷相类型、聚合物基体类型、组成和界面连通性外，其形态也对其电学特性有显著影响。因此，本文通过流延工艺，使用不同类型的BST填料[即无定形零维（0D）-BST、棒状一维（1D）-BST和片状二维（2D）-BST]设计并制备了三明治结构的BST/PVDF层状复合材料。研究了三明治结构BST/PVDF复合材料的微观结构和电学特性与BST形态的关系。讨论了不同界面模型的内部机制对BST/PVDF复合材料击穿强度的影响。根据我们的研究结果，与0D-BST和1D-BST粉末不同，2D-BST粉末由于其独特的片状形态，在三明治结构复合材料中形成多尺度平行界面，从而提高了三明治结构复合材料的击穿强度。含有2D-BST粉末的三明治结构BST/PVDF复合材料具有良好的电学特性，储能密度为19.71 J/cm，储能效率为85.3%，介电常数为30.4（1 kHz），介电损耗为0.036（1 kHz），介电可调性为93.2%。本研究提供了一种制备具有高介电可调性和高储能特性的功能复合材料的方法。
