柔性复合电介质GQDs/BTO/PVDF制备及介电储能性能研究  

Study on the preparation and energy storage performance of GQDs/BTO/PVDF flexible composite dielectrics

作　　者：熊崇浩 顾旭航 张帆 胡海龙[2] 罗行 张斗 XIONG Chonghao;GU Xuhang;ZHANG Fan;HU Hailong;LUO Hang;ZHANG Dou(School of Minerals Processing and Bioengineering,Central South University,Changsha 410083,China;Research Institute of Aerospace Technology,Central South University,Changsha 410083,China;Powder Metallurgy Research Institute,Central South University,Changsha 410083,China)

机构地区：[1]中南大学资源加工与生物工程学院,湖南长沙410083 [2]中南大学航空航天技术研究院,湖南长沙410083 [3]中南大学粉末冶金研究院,湖南长沙410083

出　　处：《中南大学学报（自然科学版）》2024年第8期3180-3193,共14页Journal of Central South University:Science and Technology

基　　金：长沙市自然科学基金资助项目(kq2202093);湖南省自然科学基金面上资助项目(2022JJ30722);湖南省自然科学基金青年项目(2022JJ40623)。

摘　　要：基于渗流阈值理论,采用FTIR、TEM、SEM、LCR数字电桥测试仪和铁电压电测试仪等测试技术,探讨BTO含量和纳米量子点种类对GQDs/BTO/PVDF复合体系介电性能的影响。研究结果表明:随着BTO质量分数的增加,体系的相对介电常数呈现先增后减的趋势,在BTO质量分数为10%时达到最大值290(5 kHz时),而介电损耗则呈现出先减小后增大的变化规律;由于―NH2官能团的引入,GQDs的电子结构被改变,从而提高了电荷传输效率;量子点材料的加入不仅能够维持高击穿场强,而且能提高BTO在基体中的分散性和体系的相对介电常数,GQDs-NH2/BTO/PVDF体系的介电性能优良,在5 kHz时相对介电常数达4713,有限元数值分析结果验证了介电性能的提升机理。GQDs-NH2/BTO/PVDF复合膜在210 kV/mm的外加电场下,储能密度达2.57 J/cm^(3),能量效率达78.8%。Based on percolation threshold theory,the effects of barium titanate(BTO)content and quantum dot types on the dielectric properties of graphene quantum dots GQDs/BTO/polyvinylidene fluoride(PVDF)composites were investigated.The dielectric constant and loss were characterized by Fourier transform infrared spectroscopy(FTIR),transmission electron microscopy(TEM),scanning electron microscopy(SEM)and LCR measurements.Ferroelectric-piezoelectric testing was also performed to evaluate the energy storage density and efficiency.Finite element analysis was used to discuss and verify the mechanism of dielectric property improvement.The results indicate that when the BTO content increases,the relative dielectric constant of the system first increases and then decreases,reaching a maximum value of 290(5 kHz)at 10%BTO content.In contrast,the dielectric loss follows as reducing first and then increasing.The introduction of—NH2 functional groups alters the electronic structure of GQDs,thereby improves charge transfer efficiency.Moreover,the addition of quantum dot materials improves the dispersion of BTO in the matrix and enhances the relative dielectric constant of the composite system while maintaining a high breakdown field strength.This effect is most pronounced in the GQDs-NH2/BTO/PVDF system,where the dielectric constant reaches 4713 at 5 kHz.For GQDs-NH2/BTO/PVDF composites,an energy storage density of 2.57 J/cm^(3)with an energy efficiency of 78.8%is achieved in an applied electric field of 210 kV/mm.This study demonstrates the effectiveness of GQDs in enhancing the dielectric performance of composite dielectrics and provides a novel research direction for improving the energy storage performance in flexible composite dielectrics.

关 键 词：纳米量子点 介电储能 钛酸钡 石墨烯量子点 柔性介电材料 

分 类 号：TB332[一般工业技术—材料科学与工程] TD98[矿业工程—选矿]