热塑性聚酰亚胺/氧化铝三明治结构柔性电介质薄膜的设计制备及其高温介电储能性能  

Design,fabrication,and high-temperature dielectric energy storage performance of thermoplastic polyimide/aluminum oxide sandwich-structured flexible dielectric films

作　　者：卓俊添 林铭浩 张齐艳 黄双武 Zhuo Jun-Tian;Lin Ming-Hao;Zhang Qi-Yan;Huang Shuang-Wu(State Key Laboratory of Radio Frequency Heterogeneous Integration,Shenzhen University,Shenzhen 518060,China;College of Electronics and Information Engineering,Shenzhen University,Shenzhen 518060,China)

机构地区：[1]深圳大学,射频异质异构集成全国重点实验室,深圳518060 [2]深圳大学电子与信息工程学院,深圳518060

出　　处：《物理学报》2024年第17期266-276,共11页Acta Physica Sinica

基　　金：国家自然科学基金青年科学基金(批准号:52203096);深圳市科技创新计划(批准号:RCBS20221008093110036,ZDSYS20220527171402005)资助的课题.

摘　　要：介电电容器具有功率密度高、充放电速度快、损耗低及循环稳定性好等优点,在先进电子和电力系统中发挥了重要的应用.聚合物电介质凭借其高击穿强度、柔性和易加工等优点,成为高电压电容器的首选材料.然而,其较低的温度稳定性难以满足新能源汽车和光伏发电等新兴领域对高工作温度的需求.本文利用物理气相沉积技术,在具有高玻璃化转变温度(T_(g))的热塑性聚酰亚胺(TPI)薄膜表面沉积氧化铝(Al_(2)O_(3))镀层,制备了有机/无机三明治结构的Al_(2)O_(3)/TPI/Al_(2)O_(3)电介质薄膜.研究结果显示,氧化铝镀层不仅与TPI之间具有优异的界面结合性,还提高了肖特基势垒,抑制了电极电荷的注入,从而降低了高温下的漏电流,并提高了击穿强度.制备的Al_(2)O_(3)/TPI/Al_(2)O_(3)三明治结构薄膜在高温下获得了优异的放电能量密度(Ud)和充放电效率(η).例如,在150和200℃高温下,η>90%时的Ud分别达到4.06和2.72 J/cm^(3),相比纯TPI薄膜提升了98.0%和349.4%.Dielectric capacitors are essential components in advanced electronic and power systems due to their high power densities,fast charge-discharge rates,low losses,and excellent cycling stabilities.Polymer dielectrics,such as biaxially oriented polypropylene(BOPP),are preferred dielectric materials for high-voltage capacitors because of their high breakdown strength,flexibility,and easy processing.However,their relatively low thermal stability limits their applications in high-temperature environments,such as in electric vehicles and photovoltaic power generation systems.In this study,sandwich-structured dielectric films are prepared by using physical vapor deposition(PVD)to deposit aluminum oxide(Al_(2)O_(3))layers onto thermoplastic polyimide(TPI)films to achieve high capacitive energy storage at high temperatures.The TPI films are chosen for their high glass transition temperature(T_(g)),while Al_(2)O_(3)layers are deposited to enhance the Schottky barrier,thereby suppressing electrode charge injection,reducing leakage current,and improving breakdown strength at high temperatures.Various characterization techniques are employed to assess the microstructure,dielectric properties,and energy storage performance of the prepared Al_(2)O_(3)/TPI/Al_(2)O_(3)sandwich-structured films.The results demonstrate that the Al_(2)O_(3)coating exhibits excellent interfacial adhesion with TPI films,successfully inhibiting charge injection and thereby reducing leakage current.For instance,at 150℃and 250 MV/m,the leakage current density of TPI film is 3.19×10^(-7) A/cm^(2),whereas for Al_(2)O_(3)/TPI/Al_(2)O_(3)sandwich-structured film,its leakage current density is 2.77×10^(-8)A/cm^(2),a decrease of one order of magnitude.The suppression of charge injection and reduction of leakage current contribute to outstanding discharge energy density(Ud)and chargedischarge efficiency(η)at high temperatures.Specifically,at high temperatures of 150 and 200℃,the Ud reaches 4.06 and 2.72 J/cm^(3),respectively,withη>90%,i.e.increasing 98.0

关 键 词：介电电容器 能量密度 三明治结构 物理气相沉积 

分 类 号：TM53[电气工程—电器] TB383.2[一般工业技术—材料科学与工程]