【作者】 赵晓锋；

【导师】 江奇；

【作者基本信息】 西南交通大学 ， 材料科学与工程， 2010， 硕士

【摘要】 电化学超级电容器(ESC)是近年来发展起来的一种新型储能器件,具有充放电速率快、效率高,对环境无污染,循环寿命长,使用范围广等特点而受到人们的重视。而电极材料是决定其电化学性能的关键。聚苯胺(PANI)由于其合成简单,环境稳定性好,优异的电学性能成为人们的首选材料。而由于纯聚苯胺比容量偏低,循环稳定性差等缺点限制其广泛应用。碳纳米管(CNT)以其独特的电学、力学性能成为一种良好的填充材料,并成为人们研究的热点。而把碳纳米管与聚苯胺复合则可克服彼此的缺点,并能大大提高比容量。首先通过有机化学合成法使苯胺单体接枝到碳纳米管表面得到碳纳米管-苯胺材料,之后分别采用化学氧化法、有机化学接枝-电化学沉积聚合联合法和模板法制备出聚苯胺／碳纳米管复合材料。并采用透射电镜、电子扫描电镜、傅立叶红外光谱等测试手段,对材料表面形貌、成分进行了表征；采用循环伏安、恒电流充放电、循环寿命和交流阻抗等测试方法讨论所制备材料在超级电容器电极材料领域的电化学性能。具体研究内容如下：1、通过有机化学合成法,使苯胺单体接枝到碳纳米管表面,然后再经化学原位聚合法制备碳纳米管／聚苯胺复合材料。由于精确控制CNTs和PANI之间的结合,充分发挥各自的优点,使它们之间产生协同作用,使得电化学性能得以提高,其电化学比容量可达到152F／g(有机电解液)。同时并讨论不同的羧基位置对复合材料电化学性能的影响。2、采用有机化学接枝-电化学沉积聚合联合法制备CNTs/PANI纳米复合材料。首先使功能化的碳纳米管与苯胺反应制备出碳纳米管-苯胺材料,之后并在与苯胺的硫酸溶液中电化学聚合得到聚苯胺／碳纳米管复合材料,并通过不同的电化学聚合速率讨论其对复合材料电容量的影响。结果表明,在聚合速率为20mV／s时生成的聚苯胺／碳纳米管膜具有导电率高,比容量大的电容性能,在电流密度为22A／m2下充放电测试,测其单电极比容量高达397F／g。3、以无机材料Fe3O4为模板,将碳纳米管功能化后包裹在模板表面,然后再将苯胺单体接枝在CNT表面,之后采用化学氧化法,将接枝于CNT表面的苯胺单体聚合成聚苯胺,从而制备CNTs/PANI微米空心球复合材料,并在电流密度为3.4A／m2的电流密度下充放电测试,其复合材料比容量可达到185F／g(有机电解液)。更多还原

【Abstract】 In recent years, supercapacitors as the electrical energy storage systems have attracted growing attention due to quick charge and discharge rate, high efficiency, environmental pollution, long cycle life. The electrode material is the key to determine their electrochemical performances. Polyaniline(PANI) is one of the most intensively investigated conductive polymers due to its environmental stability, special electrical property, low raw material and ease of synthesis, however, because of the disadvantages of the pure polyaniline, such as the low specific capacitance, poor circle stability and so on, its universal application has been limited. Carbon nanotubes (CNTs) as a good filling material with its unique electrical, mechanical properties have been one of the most attractive areas of research. Preparing CNTs and PANI to be composite material could conquer the disadvantages of each other, and increase the specific capacitance.Firstly, the aniline was inarched on the surface of the carbon nanotubes by a series of organic reaction. Then, the aniline on the surface of the CNTs was polymerized to PANI by the in situ chemical polymerization, organic chemistry inarching-electrochemistry deposition polymerization and organic chemistry method synthesis. At last, a nanometer composite named as the CNTs/PANI composite were obtained. Constitution and morphology of the obtained CNTs/PANI composite were characterized by Fourier transform infrared spectroscope and scanning electron microscope. And the electrochemical performances of the obtained materials were tested by the cyclic voltammograms, galvanostatic charging/discharging, cycles life, and electrochemical impedance spectroscopy. Specific studies are as follows:1、Through organic synthesis, the aniline was grafted on the surface of the carbon nanotubes by series of organic chemistry reactions. Then, the aniline grafted on the CNTs was polymerized to polyaniline by in-situ chemical polymerization. Because of the precise control combination of CNTs and PANI and giving full play to their strengths, it create synergies between them. At last, the methods improve the electrochemical properties. Electrochemical specific capacity can reach 152F/g (organic electrolyte). At the same time,we discuseed that carboxyl different locations of composites have also impact on electrochemical performances of composites.2、Preparation of carbon nanotubes/polyaniline nano-composites by organic chemistry inarching-electrochemistry deposition polymerization.Firstly carbon nanotubes-aniline materials were prepared by the reaction of functionalized carbon nanotubes and aniline. Then, the CNTs with the aniline and the other aniline were polymerized in the sulfuric acid solution on the surface of stainless steel by electrochemistry cyclic voltammetry deposition method at the different scanning rate. The experimental results showed that the scanning rate was 20mV/s, the obtained composite had the best conductivity and electrochemical capacitance. The single-electrode special capacitance was up to 397F/g with the 22A/m2 charging-discharging current density.3、In this paper, the Fe3O4 was used as a template to prepare carbon nanotube (CNT)/polyaniline (PANI) composite. Firstly, the aniline was grafted on the surface of the CNT by series of organic chemistry reactions. The CNT was absorbed on the surface of the Fe3O4 oxide. Then, the aniline grafted on the CNT was polymerized to PANI by in-situ chemical polymerization. At last, a hollow sphere structure composite was obtained. And the obtained CNTs/PANI composite had high specific capacitance of 185F/g (organic electrolyte) at the current density of 3.4A/m2.更多还原