高性能钛酸钡基复合薄膜超级电容器的制备及性能研究

发布时间：2018-04-23 05:32

本文选题：钛酸钡 + 超级电容器　；参考：《中国海洋大学》2015年硕士论文

【摘要】：钛酸钡材料具有高介电常数、高击穿强度而被电子工业广泛应用。钛酸钡基超级电容器具有全固态、耐高压等性能,但是其在低频区介电损耗较大,自放电现象较严重,这就限制了钛酸钡基超级电容器的应用与发展。所以研究的方向应该侧重于降低电介质材料的介电损耗,进而获得在低频区具有高介电性能和高容量性能的超级电容器。本文旨在钛酸钡周围引入一层氧化物,制备性能优异的钛酸钡基复合薄膜材料,并且对复合薄膜材料的低频介电性能进行探究,对其结构与性能的关系进行分析,然后组装超级电容器,探讨其低频容量性能及低频测试的稳定性。主要内容和结果如下：1.采用石墨纸做电极,在钛酸钡周围引入一层氧化物(B203单层薄膜、B2O3-SiO2复合薄膜),探讨了SiO2与B2O3的最佳混合比例为3：1,成功制备了B2O3-SiO2复合薄膜层。通过不同温度处理B2O-SiO2/BaTiO3薄膜可以得出900℃是最佳的处理温度,介电层在900℃时表现出了优异的介电性能,在1Hz时介电常数为1108,介电损耗为0.4345。通过不同升温速率对比,可以得出2℃/min的升温速率,能够促进B2O3-SiO2的熔融,并且形成均匀层,促进介电层介电性能的提高。此外,通过多片叠加,成功制备了B2O3-SiO2/BaTiO3超级电容器。2.采用价格低廉的铝片作为电极材料,采用在空气中热处理的方法,使钛酸钡与铝电极表面生成一层热氧化膜,使电极与氧化物一体化,通过不同的热处理制度来影响热氧化膜的形成和铝电极的存在状态,进而提高电极与氧化铝层的有效接触面积及氧化铝的含量,热处理最优条件为：10℃/min、120min,在500mHz下的钛酸钡电容器的介电常数最大,达到3.84×104,介电常数在低频区的增加较为明显,介电损耗最低为0.2801,电容器的电容最大,达到2.92gF,最终降低了介电损耗,提高了Al/Al2O3/BaTiO3超级电容器的容量。3.选用三乙醇胺作为处理液,通过化学转化法使铝电极表面生成化学转化膜(一水合软铝石),最终提高薄膜中氧化铝的含量。通过一定的氧化处理制度,来改变生成氧化铝的结构和形态,确定了最优氧化条件：氧化速率为10℃/min,氧化时间为30min。氧化铝的存在可以促进钛酸钡在低频区的介电和电容性能的提升,在500mHz下介电常数为3.84×104,电容值达到3.95μF,并通过100V、200V、300V高电压充放电,得出了电容器的容量密度及其耐压性。通过等效电路拟合探究了氧化铝和钛酸钡膜层的电化学性能,验证了钛酸钡和氧化铝膜层的结合结构,证明了电介质层中有氧化铝的存在。此外,通过对比有无三乙醇胺处理的电容器的性能,可以得出用三乙醇胺处理的电容器的具有更优异的介电和容量性能,三乙醇胺处理在制备Al/Al2O3/BaTiO3超级电容器中起到了重要的作用。4.采用全新的EIS固定频率测试法,对Al/Al2O3/BaTiO3超级电容器的低频测试稳定性进行了探讨,探讨了振幅、测试周期、频率对电容器电容测试稳定性的影响,研究结果得出振幅、测试周期、频率对稳定性都有一定影响,其中频率影响最大。并且建立测试周期与频率之间的等效公式模型,为本体系实验缩短测试时间和提高EIS测试效率提供了可行性。
[Abstract]:Barium titanate has high dielectric constant and high breakdown strength and is widely used in the electronics industry. Barium titanate supercapacitor has all solid state and high pressure resistance. However, the dielectric loss of the barium titanate is large and the self discharge phenomenon is serious. This restricts the application and development of barium titanate supercapacitor. Therefore, the research direction should be done. The dielectric loss of dielectric materials is reduced and the supercapacitor with high dielectric properties and high capacity in low frequency region is obtained. This paper aims at introducing a layer of oxide around barium titanate to prepare barium titanate composite films with excellent properties, and explore the low frequency dielectric properties of the composite thin film materials. The relationship between structure and performance is analyzed, and then supercapacitor is assembled to discuss the low frequency capacity and stability of low frequency test. The main contents and results are as follows: 1. using graphite paper as electrode and introducing a layer of oxide (B203 single layer film, B2O3-SiO2 compound film) around barium titanate, the optimum mixing ratio of SiO2 and B2O3 is 3. 1, the B2O3-SiO2 composite film layer is successfully prepared. The best treatment temperature can be obtained by treating B2O-SiO2/BaTiO3 film at different temperatures. The dielectric layer shows excellent dielectric properties at 900 C, the dielectric constant is 1108 at 1Hz, and the dielectric loss is 0.4345. through the contrast of different heating rates, and the temperature of 2 centigrade can be obtained at /min. The rate can promote the melting of B2O3-SiO2 and form a homogeneous layer and promote the dielectric property of dielectric layer. In addition, the B2O3-SiO2/BaTiO3 supercapacitor.2. is successfully prepared by multi slice superposition, and the low price aluminum sheet is used as the electrode material. The method of heat treatment in the air is used to produce a layer of barium titanate and the aluminum electrode surface. The thermal oxidation film, which integrates the electrode with the oxide, affects the formation of the hot oxide film and the existence state of the aluminum electrode through different heat treatment systems, and then improves the effective contact area of the electrode and the alumina layer and the content of alumina. The optimal heat treatment condition is: the dielectric constant of the barium titanate capacitor at 10, /min, 120min, and 500mHz The maximum number is 3.84 * 104, the dielectric constant increases more obviously in the low frequency area, the dielectric loss is lowest 0.2801, the capacitor has the maximum capacitance, the dielectric loss is 2.92gF, the dielectric loss is reduced and the capacity of Al/Al2O3/BaTiO3 supercapacitor is improved by using triethanolamine as the treatment solution, and the surface of aluminum electrode is generated by chemical conversion method. The conversion film (one hydrated bauxite) is used to improve the content of alumina in the film. Through a certain oxidation treatment system, the structure and morphology of the alumina are changed, and the optimum oxidation condition is determined: the oxidation rate of 10 C and the oxidation time of 30min. alumina can promote the dielectric and capacitance of barium titanate in the low frequency region. The dielectric constant is 3.84 * 104 at 500mHz and the capacitance is 3.95 mu F. The capacity density and pressure resistance of the capacitor are obtained by 100V, 200V, 300V high voltage charge and discharge. The electrochemical performance of the alumina and barium titanate film is investigated by the equivalent circuit fitting, and the binding structure of barium titanate and alumina film is verified. It is clear that there is the presence of alumina in the dielectric layer. In addition, by comparing the performance of the capacitors treated with triethanolamine, it can be concluded that the capacitors with triethanolamine have better dielectric and capacity properties. Triethanolamine treatment plays an important role in the preparation of Al/Al2O3/BaTiO3 super electric containers and.4. uses a new E. IS fixed frequency test method is used to investigate the stability of low frequency test of Al/Al2O3/BaTiO3 supercapacitor. The influence of amplitude, test period and frequency on the stability of capacitor capacitance test is discussed. The results show that amplitude, test period and frequency have a definite influence on the stability of the capacitor, among which the frequency has the greatest influence. And the test period is established. The equivalent formula between frequency and frequency provides feasibility for shortening the testing time and improving the efficiency of EIS test.

【学位授予单位】：中国海洋大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TM53;TB383.2

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