Xie Haoran, Wang Lu, Gao Xu, Luo Hang, Liu Lihong, Zhang Dou
State Key Laboratory of Powder Metallurgy, Central South University, Changsha, Hunan 410083, China.
Pittsburgh Institute, Sichuan University, Chengdu, Sichuan 610207, China.
ACS Omega. 2020 Dec 9;5(50):32660-32666. doi: 10.1021/acsomega.0c05031. eCollection 2020 Dec 22.
All-organic dielectric composites are drawing increased attention owing to their high operating voltage, low loss, and superior processability. However, polymers usually possess a relatively lower dielectric constant than most the other dielectrics, which seriously suppresses the improvement of their energy density. In this work, multilayer-structured composites with excellent dielectric and energy storage properties are prepared by the stacking method, and the effect of layer numbers on the performance of the composites is studied. High-κ polymers such as poly(vinylidenefluoride) (PVDF) and poly(vinylidenefluoride-ter-trifluoroethylene-ter-chlorotrifluoroethylene) (P(VDF-TrFE-CTFE)) are used to prepare the composites with different layers. It is found that the dielectric constant is up to 14.45 at 1 kHz, which is increased with the volume fraction of the P(VDF-TrFE-CTFE) layer and layer number of the composites. Due to the increased dielectric constant, an ultrahigh discharge energy density of 18.12 J/cm is achieved at the electric field of 620 kV/mm. This study exhibits an effective routine to prepare flexible high-performance dielectric materials.
全有机介电复合材料因其高工作电压、低损耗和优异的加工性能而受到越来越多的关注。然而，聚合物的介电常数通常比大多数其他电介质相对较低，这严重抑制了其能量密度的提高。在这项工作中，通过堆叠法制备了具有优异介电和储能性能的多层结构复合材料，并研究了层数对复合材料性能的影响。使用高κ聚合物，如聚偏氟乙烯（PVDF）和聚（偏氟乙烯-三氟乙烯-氯三氟乙烯）（P（VDF-TrFE-CTFE））来制备不同层数的复合材料。发现在1 kHz时介电常数高达14.45，其随P（VDF-TrFE-CTFE）层的体积分数和复合材料的层数增加而增大。由于介电常数的增加，在620 kV/mm的电场下实现了18.12 J/cm的超高放电能量密度。这项研究展示了一种制备柔性高性能介电材料的有效方法。
