PEI/BNNS复合电介质陷阱分布对击穿概率和储能性能的影响研究  

Effect of Trap Distribution on Breakdown Probability and Energy Storage Performance of PEI/BNNS Composite Dielectrics

作　　者：刘艺辰 闵道敏[1] 高梓巍 王泊心 武庆周[2] 崔浩喆 LIU Yichen;MIN Daomin;GAO Ziwei;WANG Poxin;WU Qingzhou;CUI Haozhe(State Key Laboratory of Electrical Insulation and Power Equipment,Xi’an Jiaotong University,Xi’an 710049;Institute of Fluid Physics,China Academy of Engineering Physics,Mianyang 621900;Qingdao Power Supply Company,State Grid Shandong Electric Power Company,Qingdao 266002)

机构地区：[1]西安交通大学电力设备电气绝缘国家重点试验室,西安710049 [2]中国工程物理研究院流体物理研究所,绵阳621900 [3]国网山东省电力公司青岛供电公司,青岛266002

出　　处：《电气工程学报》2024年第4期384-396,共13页Journal of Electrical Engineering

基　　金：国家自然科学基金面上(52077162);国家自然科学基金委员会与中国工程物理研究院联合基金(U1830131)资助项目。

摘　　要：能量存储设备趋于小型化、灵活化,对介电储能电容器的储能性能提出更高要求。聚醚酰亚胺(Polyetherimide,PEI)拥有稳定的化学性能和高击穿强度,是优异的储能聚合物电介质材料,但是介电储能电容器击穿场强分散性大,能量密度低是亟需解决的关键问题。通过原位聚合法制备了以聚乙烯亚胺(PEI)为基体和以氮化硼纳米片(Boron nitride nanosheets,BNNS)为填料的PEI/BNNS纳米复合电介质,测试试样的化学基团、微观形貌和电学性能。发现BNNS在PEI基体中分散均匀。随着BNNS含量增加,PEI/BNNS纳米复合电介质的极化强度逐渐增大,陷阱能级先增大后减小,击穿强度和威布尔分布形状参数也先增大后减小。然后,采用电荷捕获与分子链位移击穿模型仿真得到PEI/BNNS纳米复合电介质的击穿概率。对比仿真与试验结果反演得到纳米复合电介质的陷阱分散特性。随着掺杂含量的增加,陷阱能级期望值先增大后减小,陷阱对载流子捕获作用的变化导致威布尔特征击穿场强先增大后减小,储能密度呈现相同变化规律;陷阱分布方差先减小后增大,使得威布尔分布形状参数先增大后减小。研究结果表明,适量BNNS掺杂能够形成能级深且分散性小的陷阱,是提升复合电介质的击穿和储能性能、降低击穿分散性的关键。Energy storage equipment tends to be miniaturized and flexible,which puts forward higher requirements for the energy storage performance of dielectric energy storage capacitors.Polyether imide(PEI)has stable chemical properties and high breakdown strength,and is an excellent energy storage polymer dielectric material.However,the key problems that need to be solved are the large dispersion of breakdown field strength and low energy density of dielectric energy storage capacitors.PEI/BNNS nanocomposite dielectrics with PEI as matrix and boron nitride nanosheets(BNNS)as filler are prepared by in-situ polymerization.The chemical groups,micro morphology and electrical properties of the samples are tested.It is found that BNNS is uniformly dispersed in PEI matrix.With the increase of BNNS content,the polarization intensity of PEI/BNNS nanocomposite dielectric gradually increases,the trap energy level increases first and then decreases,the breakdown strength and Weibull distribution shape parameters also increase first and then decrease. Then, the breakdown probability of PEI/BNNS nanocomposite dielectrics issimulated by charge trapping and molecular chain displacement breakdown model. The trap distribution characteristics ofnanocomposite dielectrics are obtained by comparing the simulation and experimental results. With the increase of doping content, theexpected value of trap energy level increases first and then decreases. The change of trapping effect of traps on carriers causes thebreakdown field strength of Weibull characteristic to increase first and then decrease, and the energy storage density shows the samechange law, the variance of trap distribution decreases first and then increases, which makes the shape parameters of Weibulldistribution increase first and then decrease. The results show that a proper amount of BNNS doping can form a trap with deep energylevel and small dispersion, which is the key to improve the breakdown and energy storage performance of the composite dielectric andreduce the breakdown d

关 键 词：聚醚酰亚胺 威布尔分布 击穿场强 纳米掺杂 形状参数 陷阱能级 

分 类 号：TM211[一般工业技术—材料科学与工程]