核壳结构SiCNWs@SiO_(2)/PVDF复合材料的制备与介电储能特性  

Preparation and Dielectric Energy Storage Properties of CoreShell Structure SiCNWs@SiO_(2)/PVDF Composites

作　　者：苏宇 翁凌[1,2] 王小明 关丽珠 张笑瑞[1,2] SU Yu;WENG Ling;WANG Xiaoming;GUAN Lizhu;ZHANG Xiaorui(School of Materials Science and Chemical Engineering,Harbin University of Science and Technology,Harbin 150080,China;Key Laboratory of Engineering Dielectric and Its Application,Ministry of Education,Harbin University of Science and Technology,Harbin 150040,China)

机构地区：[1]哈尔滨理工大学材料科学与化学工程学院,哈尔滨150080 [2]哈尔滨理工大学工程电介质及其应用教育部重点实验室,哈尔滨150040

出　　处：《材料导报》2023年第11期190-200,共11页Materials Reports

基　　金：国家自然科学基金(51677045);哈尔滨理工大学“理工英才”优秀青年基金(2019-KYYWF-0206)。

摘　　要：为了加速新能源电子器件向微型化和集成化的方向发展,提高电子器件内部介电复合材料的性能至为重要,介电复合材料的介电性能和储能性能直接影响电子器件的质量,如何提高介电复合材料的介电性能和储能性能等引起了研究者们的广泛关注。以聚偏氟乙烯(PVDF)为基体,碳化硅纳米线(SiCNWs)和核壳结构碳化硅纳米线@二氧化硅(SiCNWs@SiO_(2))为填料,通过溶液共混相转换法及热压工艺制备出一系列的SiCNWs/PVDF二元复合材料和SiCNWs@SiO_(2)/PVDF复合材料。探究介电纳米填料的表面修饰对PVDF基复合材料的微观结构、宏观介电性能和储能性能等的影响。实验结果表明,硅烷偶联剂KH550成功改性SiCNWs;通过一步法热氧化工艺成功制备出具有典型核壳结构的SiCNWs@SiO_(2)纳米线,SiO_(2)壳层的厚度随着SiCNWs热氧化时间的延长而增大,当SiCNWs热氧化时间为10 h,SiO_(2)壳层的厚度为6.5 nm;采用相转换法和热压处理成功制备一系列的SiCNWs/PVDF二元复合材料和SiCNWs@SiO_(2)/PVDF复合材料,SiCNWs和SiCNWs@SiO_(2)与PVDF基体成功复合;当SiCNWs掺杂量较大时,SiCNWs/PVDF二元复合材料出现明显的团聚现象,核壳结构SiCNWs@SiO_(2)纳米线的引入,有效地提升纳米填料在聚合物基体中的分散性。对比纯PVDF,SiCNWs的引入大幅度提高了复合材料的介电常数,但其介电损耗和电导率较大。将核壳结构SiCNWs@SiO_(2)纳米线嵌入PVDF基体中,使复合材料在保持高介电常数的同时不同程度地降低了介电损耗和电导率,同时复合材料的击穿强度也有较大的提升。25%(质量分数)SiCNWs@SiO_(2)/PVDF(10 h)复合材料在极限电场强度下获得的最大放电能量密度分别为0.111 J/cm 3,获得的放电效率分别为53.06%,有效提升了复合材料的储能性能。In order to accelerate the development of new energy electronic devices towards miniaturization and integration,it is very important to improve the properties of dielectric composites in electronic devices.The dielectric properties and energy storage properties of dielectric composites directly affect the quality of electronic devices.How to improve the dielectric properties and energy storage properties of dielectric composites has attracted extensive attention of researchers.Based on polyvinylidene fluoride(PVDF),silicon carbide nanowires(SiCNWs),core-shell silicon carbide nanowires@silica(SiCNWs@SiO_(2))as filler,a series of SiCNWs/PVDF binary composites and SiCNWs@SiO_(2)/PVDF composites were prepared by solution blending phase conversion method and hot pressing process.The effects of surface modification,core-shell structure on the microstructure,and the corresponding macro dielectric properties and energy storage properties of PVDF matrix composites were investigated.The experimental results show that:SiCNWs were modified by silane coupling agents KH550,typical core-shell structures were prepared by one-step thermal oxidation process SiCNWs@SiO_(2)nanowires,the thickness of SiO_(2)shell increases with the extension of thermal oxidation time,when the thermal oxidation time is 10 h,the thickness of SiO_(2)shell is 6.5 nm;PVDF matrix composites were synthetized by phase conversion method,and all nano fillers were blended with PVDF matrix;With the doping amount of SiCNWs increasing,the SiCNWs/PVDF binary composite appears obvious agglomeration.The addition of SiCNWs@SiO_(2)can greatly improved the dispersion of fillers in polymer matrix.Compared with pure PVDF,the introduction of SiCNWs greatly enhances the dielectric constant of the composites.However,its dielectric loss and conductivity are still large.The core-shell structure can effectively reduce the dielectric loss and conductivity while maintaining high dielectric constant,and significantly improve the breakdown strength of the composites.The energy stor

关 键 词：聚偏氟乙烯 碳化硅纳米线 核壳结构 介电性能 储能密度 

分 类 号：TB332[一般工业技术—材料科学与工程]