多孔炭材料的可控制备及其电化学性能研究

发布时间：2018-07-05 14:52

本文选题：超级电容器 + 模板法　；参考：《哈尔滨工程大学》2014年博士论文

【摘要】：超级电容器具有较高的功率密度、优异的倍率性能、快速充/放电特性、超长的循环寿命以及原理简单、维护费用低等优点,因此在世界范围内引起了科研工作者的广泛关注。炭材料具有较高的比表面积及良好的导电性被广泛应用于超级电容器的电极材料。研究表明,炭材料的电化学性能与其比表面积、孔结构和表面化学性质密切相关。本论文采用不同的模板制备了具有不同形貌和孔结构的多孔炭材料,并采用扫描电子显微镜、透射电子显微镜、X射线衍射、拉曼光谱、X射线光电子能谱等技术对多孔炭材料的微观结构和表面性质进行表征,采用循环伏安法、恒流充放电法及交流阻抗法详细研究了电极材料的电化学性能。以中孔SiO_2为模板,以沥青为碳源经过高温碳化制备了中孔炭材料(MCSF)。结果表明,制备的MCSF具有较高的比表面积(582 m2·g-1)。当扫描速度为5 mV·s-1时,MCSF电极比容量最高可达264 F·g-1;当扫描速度增大至1000 mV·s-1时其比容量为194 F·g-1,保持率为74%,表明该电极材料具有优异的倍率特性。连续循环5000次后其比容量仅衰减了 9%,说明MCSF具有优异的电化学稳定性。组装的对称电容器能量密度可达9.6 Wh·kg-1,其最大功率密度可达119.4 kW·kg-1。以CNTs/MnO_2为模板,以C_2H_2为碳源,采用化学气相沉积法制备了 CNT-HCS。研究结果表明,CNT-HCS的比表面积可达500.6 m2·g-1。当电流密度为0.5 A·g-1时,其比容量可达201.5 F·g-1。另外,CNT-HCS电极具有优异的倍率特性,当电流密度升高到20 A·g-1时,比容量仍能保持69%。组装的对称电容器能量密度最高可达11.3 Wh·kg-1。分别以花瓣状ZnO、沥青、KOH为模板、碳源和活化剂,采用高温碳化、活化的方法制备了具有花瓣状结构的分层次多孔炭材料(FHPC)。当扫描速度为2 mV·s-1时FHPC电极的比容量可达294 F·g-1。当扫描速度为500 mV·s-1时,比容量仍能保持71%,说明FHPC电极具有优异的电化学性能。组装的FHPC//FHPC对称电容器在1 mol·L-1 Na_2SO_4溶液中能量密度可达15.9Wh·kg-1。由于其优异的倍率特性,对称电容器的功率密度可达222kW·kg-1。采用Mg(OH)2为模板在低温下制备了富含含氧官能团的石墨烯FGN-300。系统研究了热处理温度对材料表面化学性质及电化学性能的影响。研究结果表明,当热处理温度为300℃时材料具有优异的电化学性能。FGN-300不仅具有较高的质量比容量而且具有很高的体积比容量,在6 mol·L-1 KOH溶液中其积比容量可达470 F·cm-3。另外,组装的对称电容器在水性电解液中具有超高的体积能量密度(27.2 Wh·L-1)和较高的循环稳定性,循环10000次后,其比容量是初始容量的134%。优异的电化学性能主要归因于其较高的有效比表面积、较低的孔体积以及稳定的含氧官能团。因此,FGN-300有望满足对紧凑型便携式能量存储装置的需求。以石墨烯/中孔SiO_2为模板,采用原位聚合法制备了石墨烯/中孔聚苯胺复合材料(G-mPANI)。研究发现,制备的G-mPANI呈现较薄的片层结构,表面上包覆的PANI具有相互连接的网络结构,并且G-mPANI中存在大量中孔结构。结果表明,G-mPANI具有较高的比容量、优异的倍率特性和循环稳定性,当电流密度为0.5 A·g-1时其比容量可达749 F·g-1。优异的电化学性能主要归因于其独特的结构特点。此外,采用高温碳化的方法制备了氮掺杂多孔石墨烯(NPCG)。探讨了不同碳化温度对材料结构、表面化学性质及电化学性能的影响。结果表明当碳化温度为700℃时制备的炭材料(NPCG-700)具有较高的比表面积,呈现相互连接的多孔结构,而且氮含量较高。NPCG-700电极在2 mV·s-1时质量比容量可达305 F·g-1。NPCG-700电极具有较高的体积比容量和体积能量密度,分别为287 F·cm-3和15.3 Wh·L-1。以上研究结果表明,掺杂氮原子是一种有效提高材料比容量的方法。
[Abstract]:Supercapacitors have high power density, excellent multiplier performance, fast charge / discharge characteristics, super long cycle life, simple principle and low maintenance cost, so it has aroused widespread concern in the world. Carbon materials have high specific surface area and good conductivity, which are widely used in super power. The study shows that the electrochemical properties of carbon materials are closely related to the surface area, pore structure and surface chemical properties. This paper uses different templates to prepare porous carbon materials with different morphology and pore structure, and uses scanning electron microscopy, transmission electron microscopy, X ray diffraction, Raman spectroscopy, and X shooting. The microstructure and surface properties of porous carbon materials were characterized by linear photoelectron spectroscopy. The electrochemical properties of the electrode materials were studied in detail by cyclic voltammetry, constant current charge discharge and impedance method. The mesoporous carbon materials (MCSF) were prepared by high temperature carbonization with mesoporous SiO_2 as the carbon source. The results showed that the carbon material was prepared by high temperature carbonization. The prepared MCSF has a high specific surface area (582 m2. G-1). When the scanning speed is 5 mV. S-1, the specific capacity of the MCSF electrode is up to 264 F. G-1. When the scanning speed increases to 1000 mV s-1, the specific capacity is 194 F. The retention rate is 74%, indicating that the electrode material has excellent multiplier properties. After 5000 times of continuous cycle, its specific capacity attenuates only. 9%, it shows that MCSF has excellent electrochemical stability. The energy density of the assembled symmetric capacitor can reach 9.6 Wh. Kg-1. The maximum power density can reach 119.4 kW. Kg-1. with CNTs/MnO_2 as the template and C_2H_2 as the carbon source. The results of CNT-HCS. study by chemical vapor deposition show that the specific surface area of CNT-HCS can reach 500.6 m2. G-1. when When the current density is 0.5 A. G-1, its specific capacity is up to 201.5 F. G-1., and the CNT-HCS electrode has excellent multiplier characteristics. When the current density rises to 20 A. G-1, the maximum energy density of the symmetrical capacitor which can maintain 69%. assembly can be up to 11.3 Wh. Kg-1. with petal ZnO, bitumen, KOH as templates, carbon sources and activators, respectively. The layered porous carbon material (FHPC) with petal structure is prepared by high temperature carbonization and activation. When the scanning speed is 2 mV. S-1, the specific capacity of FHPC electrode can reach 294 F. G-1. when the scanning speed is 500 mV. S-1, the specific capacity can remain 71%, indicating that the FHPC electrode has excellent electrochemical properties. The assembled FHPC//FHPC symmetric capacitance is the same. The energy density of the apparatus in 1 mol L-1 Na_2SO_4 solution can reach 15.9Wh. Kg-1. due to its excellent multiplier property, the power density of the symmetric capacitor can reach 222kW. Kg-1. with Mg (OH) 2 as a template. The graphene FGN-300. system rich in oxygen rich functional groups is prepared at low temperature to study the chemical properties and electrochemistry of the material surface on the surface of the material. The results show that when the heat treatment temperature is 300 C, the material has excellent electrochemical performance.FGN-300 not only has high mass specific capacity but also has a high volume specific capacity, and the volume of the product can reach 470 F. Cm-3. in 6 mol L-1 KOH solution, and the assembled symmetric capacitor is in the water electrolyte. Ultra high volume energy density (27.2 Wh. L-1) and high cyclic stability. After 10000 cycles, the excellent electrochemical performance of its specific capacity is the initial capacity of 134%., mainly due to its higher effective specific surface area, lower pore volume and stable oxygen functional group. Because of this, FGN-300 is expected to meet the compact type of portable energy storage. The needs of the storage device. Graphene / mesoporous SiO_2 is used as a template to prepare graphene / mesoporous polyaniline composite (G-mPANI) by in situ polymerization. The study shows that the prepared G-mPANI is thin layer structure, the coated PANI has a interconnected network structure and a large number of mesoporous structures exist in G-mPANI. The results show that G- MPANI has high specific capacity, excellent multiplier characteristics and cyclic stability. When the current density is 0.5 A. G-1, the excellent electrochemical performance of its specific capacity up to 749 F. G-1. is mainly attributable to its unique structural characteristics. In addition, nitrogen doped polypore graphene (NPCG) is prepared by high temperature carbonization. The different carbonization temperature is discussed. The effect of material structure, surface chemical properties and electrochemical properties. The results show that the carbon material (NPCG-700) prepared at 700 C has a high specific surface area, a porous structure connected with each other, and the higher nitrogen content.NPCG-700 electrode has a higher mass ratio capacity of 305 F. G-1.NPCG-700 electrode at 2 mV. The volume specific capacity and volume energy density of 287 F. Cm-3 and 15.3 Wh. L-1. respectively show that the doping of nitrogen atom is an effective method to improve the specific capacity of the material.
【学位授予单位】：哈尔滨工程大学
【学位级别】：博士
【学位授予年份】：2014
【分类号】：TM53;TQ127.11

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