核壳结构功能颗粒构建策略与聚合物介电/储能特性的关系

Construction strategies of core-shell structured functional nanoparticles and their influence on dielectric properties and energy storage of polymer-based composites

具有高功率密度及优异的力学性能的聚合物基电介质材料,被认为是具有巨大潜力的新能源材料之一。然而,由于聚合物材料介电常数较低,导致储能密度较低,目前很难获得大规模储能应用。材料的储能密度大小主要由其介电常数与击穿场强决定。因此,如何实现复合材料介电常数和击穿场强的同时提高,是该领域最大的理论和实践挑战。近年来,通过构建具有多层结构的核壳功能颗粒作为填料,可以有效改善上述问题。本文阐述了聚合物基介电复合材料发展的应用与挑战,介绍了提高其介电常数的主要方法。并对近期关于各种代表性核壳结构功能颗粒如聚合物壳层、无机壳层、碳壳层以及金属壳层的构建策略,及其作为功能填料对聚合物介电储能特性的机理和影响进行了总结,并对其未来的发展方向提供建议。合理构建核壳结构的功能颗粒可以有效提高界面面积及界面极化效应,是目前同时提升纳米复合材料介电性能与储能性能最有效的策略之一。

Polymer-based dielectric energy storage composites with high power density and excellent mechanical properties are considered as one of the promising new-energy materials.However,due to its low dielectric permittivity of polymer materials,resulting in lower energy storage density,it is difficult to develop in large-scale application.The energy storage density of composites is mainly determined by their dielectric permittivity and breakdown strength.Thus,how to improve the permittivity and breakdown field strength of composites simultaneously is a great theoretical and practical challenge in this field.In recent years,this problem can be effectively improved by constructing a core-shell functional filler.This paper firstly reviewed the application and challenges of polymer-based dielectric composites,and the main methods to improve the dielectric permittivity.Then the recent construction strategy of various representative core-shell structured functional particles,such as polymeric shell,inorganic shell,carbon shell and metallic shell,as well as the mechanism and influences of the energy storage characters of polymer-based composites were summarized.The future directions of development were also suggested.It is one of the most effective strategies to improve the dielectric and energy storage properties of nanocomposites at the same time by reasonably constructing functional particles with core-shell structure to effectively improve the interfacial area and interfacial polarization.