具有正/负介电叠层结构的新型高介电材料构筑及性能调控

With the development of dielectric capacitors towards high integration and high energy density, it is urgent for us to explore novel high dielectric (high-k) materials with simultaneous high dielectric constant, high breakdown strength and low loss. The development of high-k materials has always been hindered by the phenomenon that high dielectric constant is usually accompanied by high loss and low breakdown strength. To solve the problem, we propose the construction of novel high-k materials consisting of alternating positive-k and negative-k layers. Recently, we experimentally proved that the introduction of negative-k layers could realize a significant enhancement of dielectric constant without sacrificing the low loss. Currently, there is no report about positive-k/negative-k multilayer materials. Therefore, comprehensive experimental and theoretical investigations are needed to illuminate the abundant physical connotations of this novel kind of high-k materials with complicated multilevel interfaces and various polarizations, resulting in the performance manipulation and optimization. The following researches will be carried out in this project: controllable preparation and modification of dielectric functional units; fabrication and performance manipulation of single-layer dielectric composites; construction and performance manipulation of multilayer composites with alternating negative-k and positive-k layers; revealing the underlying mechanisms that control the synergistic effects between negative-k and positive-k materials. This project will provide a theoretical basis for the construction of novel high-k materials, and it is also significant for the development of negative-k materials.

随着电介质电容器向高度集成化和高储能密度化趋势发展，迫切需要开发兼具高介电常数、高击穿强度和低损耗的新型高介电材料。一直以来，限制高介电材料发展的一大难题在于高介电常数往往伴随着高损耗和低击穿强度。针对该问题，申请人提出引入负介电材料，构筑具有正/负介电叠层结构的新型高介电材料。课题组前期实验验证了负介电层的引入可在保持低损耗的同时显著提高介电常数。目前，关于正/负介电叠层材料的研究尚未见报道。由于正/负介电叠层材料内部存在复杂的多级界面和多种极化，需要深入的实验和理论研究以阐明其丰富的物理内涵，进而实现性能调控和优化。因此，本项目拟重点开展以下研究：介电功能体的可控制备和改性；单层介电复合材料的制备和性能调控；正/负介电叠层材料的构筑及性能优化；阐明正、负介电材料协同作用机理。本项目可为构筑新型高介电材料提供理论依据，对负介电材料的发展也有重要意义。

随着电介质电容器向小型化和高度集成化发展，迫切需要开发具有高介电常数、低损耗和高击穿强度的新型高介电材料。一直以来，限制高介电材料发展的一大难题在于高介电常数往往伴随着高损耗和低击穿强度。针对该问题，本项目通过构筑正/负介电叠层结构、线性/非线性叠层结构和填料骨架结构，在保持低损耗和高击穿强度的同时，获得了显著提升的介电常数，为高介电材料的设计提供了有效策略。基于本项目研究，取得了以下成果：（1）在正/负介电叠层复合材料中发现了显著的介电增强效应并揭示了其微观物理机制。该研究成功地将负介电材料融入到介电储能材料领域，既为高介电材料设计提供了新思路，又拓宽了负介电材料研究领域。基于该研究，发表论文6篇，授权国家发明专利1项；（2）通过构建线性/非线性介电叠层复合材料，实现了介电常数和击穿电压协同提升，且线性层的线性极化特性赋予了该材料高充放电效率和低损耗。基于该研究，在Adv. Funct. Mater.等期刊发表论文10篇，其中ESI高被引2篇，授权国家发明专利1项；（3）对复合材料进行填料骨架和多级界面设计，在低填料含量下，实现了介电常数显著提升。基于该研究，发表论文7篇，其中ESI高被引2篇，一篇文章获Compos. Part A 期刊2021年度Highly Cited Paper Award，授权国家发明专利1项。依托本项目，项目负责人获得山东省优秀青年科学基金等科研项目3项。本研究为构筑新型高介电材料提供了理论和实验借鉴，对负介电材料的发展也有重要意义。