【作者】 戴伟杰；

【导师】 曹洁明；

【作者基本信息】 南京航空航天大学 ， 材料学， 2010， 硕士

【摘要】 超级电容器作为一种新型绿色储能装置,由于具有能量密度高、功率密度大、循环寿命长等优点,在汽车、通讯、国防等诸多领域有广泛的应用前景,日益受到国内外研究人员的关注。有序介孔碳和介孔金属氧化物具有有序的孔道结构、均一的孔径分布、高的比表面积和大的孔体积,是超级电容器的理想电极材料。制备不同孔道结构的介孔碳和介孔金属氧化物,进一步研究孔道结构对超电容性能的影响,对其在超级电容器电极材料中的应用具有重要意义。本文首先以三嵌段共聚物P123为表面活性剂、正硅酸乙酯或硅酸钠为硅源,制备出了具有有序孔道结构的介孔二氧化硅SBA-15、MSU-H和KIT-6。以二维六方结构的MSU-H和三维立方结构的KIT-6为硬模板、蔗糖为碳源,进一步合成了有序介孔碳OMC-M和OMC-K。在蔗糖中添加硼酸,通过控制硼酸的添加量,获得了在4～10 nm范围内孔径可调的有序介孔碳。对所得有序介孔碳进行循环伏安、恒流充放电和交流阻抗等电化学测试,其结果表明,在5 mV/s扫描速率下,对于两种不同结构的OMC-M和OMC-K,OMC-M-6和OMC-K-4的比电容分别达到最大值203.8和190.4 F/g。当扫描速率从5 mV/s变化到100 mV/s时,有序介孔碳的电容保持率高达81～86 %。在4～8 nm范围内,有序介孔碳的比表面电容随孔径的增大而增大,在5 mV/s扫描速率下,OMC-M-2达到最大值27.5μF/cm²。以二维六方结构的SBA-15为硬模板、金属硝酸盐为前驱体,获得了介孔结构的NiO和NiO/Co₃O₄复合物,并研究了添加柠檬酸对产物结构的影响。结果表明添加柠檬酸后,NiO和NiO/Co₃O₄复合物的比表面积由123.8和115.8 m²/g分别提高到了238.4和170.8 m²/g。电化学测试结果表明,在0.1 A/g电流密度下,添加柠檬酸后的NiO-CA和NiO/Co₃O₄-CA的比电容分别达到220.1和625.8 F/g,分别是未添加柠檬酸时的1.7和2.7倍。更多还原

【Abstract】 As a new kind of green energy storage device, supercapacitor has been of wide interest for applications in many fields, such as automobile, telecommunication, and military force, due to high energy density, high power density, and long cycle life, attracting more and more attention from researchers around the world. Ordered mesoporous carbons and mesoporous metal oxides have been recognized as ideal electrode materials due to their ordered mesoporous structures, uniform pore size distributions, high surface areas and high pore volumes. It is significative to research on the preparation of different mesoporous structures of ordered mesoporous carbons and mesoporous metal oxides and the influence of mesoporous structures on the pseudocapacitive performance.In this paper, ordered mesoporous silicas SBA-15, MSU-H, and KIT-6 were firstly synthesized by using the triblock copolymer P123 as the surfactant and TEOS or sodium silicate as the silicate precursor. Ordered mesoporous carbons OMC-M and OMC-K were further synthesized by using two-dimensional hexagonal MSU-H and three-dimensional cubic KIT-6, respectively, as the hard template and the sucrose as the carbon precursor. Ordered mesoporous carbons with tunable pore sizes in the range of 4 to 10 nm were obtained by adding some amount of boric acid in the carbon precursor. The as-synthesized samples were characterized by cyclic voltammetry, galvanostatic charge/discharge and electrochemical impedance spectroscopy experiments. The results reveal that, as to OMC-M and OMC-K, OMC-M-6 and OMC-K-4 exhibited the highest specific capacitances of up to 203.8 and 190.4 F/g, respectively, at the scan rate of 5 mV/s. All ordered mesoporous carbons maintained 81⁸6 % of the specific capacitances when the scan rate changed from 5 mV/s to 100 mV/s. The specific surface capacitances of ordered mesoporous carbons increased with the increase of the pore sizes in the range of 4 to 8 nm and OMC-M-2 reached the highest value of 27.5μF/cm² at the scan rate of 5 mV/s.Ordered mesoporous NiO and NiO/Co₃O₄ composite were synthesized by using two-dimensional SBA-15 as the hard template and corresponding metal nitrates as the precursors, and the influence of the addition of citric acid into the precursors on the structure of metal oxides was also investigated. The characterization results reveal that, because of the adding of the citric acid into the precursors, the specific surface areas of NiO and NiO/Co₃O₄ composite increased from 123.8 and 115.8 m²/g to 238.4 and 170.8 m²/g, respectively. The results of electrochemical characterization show that the specific capacitances of NiO-CA and NiO/Co₃O₄-CA reached 220.1 and 625.8 F/g, respectively, which were 1.7 and 2.7 times of the NiO and NiO/Co₃O₄.更多还原