Polymer-based dielectrics (PDs) with improved permittivity (k) have considerable applications including capacitors, actuator devices and electrical power systems due to their flexibility, easy processability and low weight, etc. However, the permittivity values of commonly used polymers (usually k < 3) fails to meet the requirements of the advanced electrical components. Enormous research, including numerical and experimental works has shown that developing polymer based multi-phase materials represents the most promising avenue. This review will clarify the concepts and relationships based on the polarization mechanisms and meanwhile some key factors of improving permittivity will also be discussed including polymer chains/segments, morphology, the interface of nanofillers-matrix, processing, and multilayer structures. Combining with the recent specific advances in PDs, the latest developments in this field will be summarized which are the introduction of polar functional groups/copolymer segments, the application of core-shell nanofillers and the technology of multi-layers structures. We hope to help readers to comprehensively understand the fabrication of PDs from the selection of molecular units to the design of composites in order to provide guidance on achieving polymer based materials with high permittivity.

具有改进的介电常数 ( k ) 的聚合物基电介质 (PD)由于其柔韧性、易加工性和重量轻等优点，在电容器、致动器装置和电力系统等方面具有相当大的应用。然而，常用聚合物的介电常数值（通常为k < 3) 不符合先进电器元件的要求。包括数值和实验工作在内的大量研究表明，开发基于聚合物的多相材料是最有前途的途径。本综述将阐明基于极化机制的概念和关系，同时还将讨论提高介电常数的一些关键因素，包括聚合物链/段、形态、纳米填料-基质的界面、加工和多层结构。结合近年来PDs的具体进展，总结了该领域的最新进展，包括极性官能团/共聚物链段的引入、核壳纳米填料的应用和多层结构技术。