Sun Shengbiao, Shi Zhicheng, Sun Liang, Liang Liang, Dastan Davoud, He Benlin, Wang Huanlei, Huang Minghua, Fan Runhua
School of Materials Science and Engineering, Ocean University of China, Qingdao 266100, P. R. China.
Department of Materials Science and Engineering, Georgia Institute of Technology, Atlanta, Georgia 30332, United States.
ACS Appl Mater Interfaces. 2021 Jun 16;13(23):27522-27532. doi: 10.1021/acsami.1c08063. Epub 2021 Jun 3.
Dielectric polymer capacitors are extensively applied in advanced electronics by virtue of their extremely high power density. However, it remains a challenge to concurrently realize high energy density and high discharge efficiency. In order to solve this conundrum, we herein design a novel all-polymer trilayer structure, where the paraelectric poly(methyl methacrylate) (PMMA) is used as the top layer to obtain a high discharge efficiency, and ferroelectric P(VDF-HFP) is employed as the bottom layer to obtain a high energy density. Particularly, the PMMA/poly(vinylidene fluoride-hexafluoropropylene) (P(VDF-HFP)) blend composite is used as the middle layer to homogenize the electric field inside the trilayer composites, turning out an obviously boosted breakdown strength and elevated energy density. Consequently, an efficiency as high as 85% and an energy density up to 7.5 J/cm along with excellent cycling stability are simultaneously realized at an ultrahigh electric field of 490 kV/mm. These attractive characteristics of the all-polymer trilayer structure suggest that the feasible pathway presented herein is significant to realize concurrently a high energy density and discharge efficiency.
介电聚合物电容器凭借其极高的功率密度在先进电子领域得到广泛应用。然而，同时实现高能量密度和高放电效率仍然是一项挑战。为了解决这一难题，我们在此设计了一种新型的全聚合物三层结构，其中顺电聚甲基丙烯酸甲酯（PMMA）用作顶层以获得高放电效率，铁电聚偏氟乙烯-六氟丙烯（P(VDF-HFP)）用作底层以获得高能量密度。特别地，PMMA/聚偏氟乙烯-六氟丙烯（P(VDF-HFP)）共混复合材料用作中间层以使三层复合材料内部的电场均匀化，从而显著提高击穿强度和能量密度。因此，在490 kV/mm的超高电场下，同时实现了高达85%的效率、7.5 J/cm³的能量密度以及优异的循环稳定性。全聚合物三层结构的这些吸引人的特性表明，本文提出的可行途径对于同时实现高能量密度和放电效率具有重要意义。
