介孔碳的制备及其用于超级电容器电极材料的研究

发布时间：2019-02-20 21:20

【摘要】：超级电容器是一种介于传统电容器和电池之间的一种新型储能元件。它具有功率密度高、充放电速率快、超高的电容量、超长的寿命、价格较低、免维护、对环境比较友善、安全性高等优点，因此受到了国内外科学家的广泛关注，可以用于信息技术、交通、国防科技和航空航天等领域，具有相当大的市场和使用前景。本论文使用无模板高温碳化法，以葡萄糖和葡萄糖与三聚氰胺混合物为前驱体，通过调节碳化过程中氮气压力来控制孔的尺寸进而制备介孔碳材料（Mesoporouscarbon—MCs）和氮掺杂介孔碳（Nitrogen-doped mesoporous carbon—NMCs）材料，实现了双电层电容和法拉第赝电容的良好结合。同时利用氮气吸附脱附分析（BET）、高分辨透射电子显微镜分析（HRTEM）、X射线光电子能谱（XPS）和循环伏安（CV）、交流阻抗（EIS）、恒流充放电等测试手段对材料的结构、形貌、电化学性能进行表征与分析。实验结果表明，在真空和不同的氮气压力下、温度为620°C保温4h制备的多孔碳材料具备一定的混乱度。在0MPa和0.02MPa氮气压力条件下，制备的多孔碳材料为微孔材料；在0.05MPa和0.1MPa氮气压力条件下，制备的多孔碳材料的孔径由微孔变为介孔，孔径分布范围分别为2～4nm和2～3.5nm。随着氮气压力的增加，孔径分布范围变窄，主要是由于高压会压缩孔体积和阻碍前驱体的分解。采用不同质量比的三聚氰胺和葡萄糖制备的NMCs材料中N1s的类型分别为吡啶型N即N-6（398.7eV）、吡啶/吡咯型N即N-5（399.8eV）和石墨型N即N-Q（401eV），原子含量分别为0.46%、1.04%和0.78%。通过电化学测试结果可知，制备的MCs材料经KOH活化后具有更好的电化学稳定性和可逆性；在氮气压力为0.05MPa下制备的MCs材料具有更高的比电容，达到250F·g-1。在电流密度为2A·g-1时，循环扫描1000圈后，，比电容衰减4%。以质量比分别为1、2、6的三聚氰胺和葡萄糖为前驱体制备NMCs，在质量比为2时，获得的NMCs材料具有更高的电容，达到442.5F·g-1。在电流密度为2A·g-1时，制备的MCs和NMCs的比电容分别为250F·g-1和442.5F·g-1。
[Abstract]:Supercapacitor is a new energy storage element between conventional capacitor and battery. It has the advantages of high power density, high charge / discharge rate, super high capacitance, long life, low price, no maintenance, friendly to the environment, high safety and so on, so it has attracted wide attention from scientists at home and abroad. Can be used in information technology, transportation, defense science and technology, aerospace and other fields, with considerable market and application prospects. In this paper, a template free high-temperature carbonization method was used. Glucose and glucose mixtures with melamine were used as precursors. The mesoporous carbon materials (Mesoporouscarbon-MCs) and nitrogen-doped mesoporous carbon (Nitrogen-doped mesoporous carbon-NMCs) materials were prepared by controlling the pore size by adjusting the nitrogen pressure during carbonation. The combination of double layer capacitance and Faraday pseudo-capacitance was achieved. At the same time, (BET), high resolution transmission electron microscopy (TEM) was used to analyze the structure of (HRTEM), X ray photoelectron spectroscopy (XPS) and cyclic voltammetry (CV),) (CV), impedance constant current charge / discharge (EIS),) measurements. The morphology and electrochemical properties were characterized and analyzed. The experimental results show that the porous carbon materials prepared at 620 掳C for 4 h under vacuum and different nitrogen pressure have a certain degree of confusion. Under the nitrogen pressure of 0MPa and 0.02MPa, the porous carbon materials are microporous materials. Under the nitrogen pressure of 0.05MPa and 0.1MPa, the pore size of the prepared porous carbon materials changed from micropore to mesoporous, and the pore size distribution ranges from 2~4nm and 2C3.5 nm, respectively. With the increase of nitrogen pressure, the pore size distribution becomes narrower, mainly because the high pressure will compress the pore volume and hinder the decomposition of the precursor. The types of N1s in NMCs materials with different mass ratios of melamine and glucose are pyridine N-6 (398.7eV), pyridine / pyrrole N-5 (399.8eV) and graphite-type N-Q (401eV), respectively. The atomic content was 0.46% and 0.78%, respectively. The electrochemical test results show that the prepared MCs material has better electrochemical stability and reversibility after KOH activation, and the MCs material prepared under the nitrogen pressure of 0.05MPa has a higher specific capacitance up to 250F g-1. When the current density is 2A g ~ (-1), after 1000 cycles of cyclic scanning, the capacitance is attenuated 4 times. NMCs, was prepared by using melamine and glucose as precursors. When the mass ratio was 2, the obtained NMCs material had a higher capacitance, reaching 442.5 F g-1. When the current density is 2A g ~ (-1), the specific capacitance of MCs and NMCs are 250F g ~ (-1) and 442.5 F g ~ (-1), respectively.
【学位授予单位】：燕山大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TM53

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