微纳米多级结构复合电极材料制备及其在超级电容器中的应用

发布时间：2018-03-05 21:11

本文选题：超级电容器　切入点：氧化镍　出处：《济南大学》2014年硕士论文　论文类型：学位论文

【摘要】：随着全球的能源缺乏和环境恶化，各种可循环的电化学储能器件愈来愈受到人们的重视。作为新式能量储存器件的超级电容器，由于其具有高的功率密度无污染、循环时长等优点，因而受到广泛关注与研究。而其性能高低关键在于电极材料的选择。鉴于金属氧化物和碳材料作为电极材料的优缺点，将金属氧化物与泡沫镍集流体、碳材料进行负载制备性能良好的复合电极材料成为材料研究学者的首要目标。本论文采用微波水热法，，围绕纳米氧化镍的制备以及采用泡沫镍或活性碳纤维布为载体负载纳米氧化镍以获取具有微纳米结构的复合材料的相关问题展开研究，采用X射线衍射仪、热分析、扫描电子显微镜等测试技术对材料的结构与形貌进行表征与观察，并通过循环伏安法、交流阻抗法对所制备电极材料的电化学性能进行测试。主要工作包括以下几个方面：采用微波水热法，以NiSO4为镍源，尿素为沉淀剂，分别选用聚乙二醇4000（PEG-4000）和聚醚酰亚胺（PEI)为表面活性剂，通过改变保温时间、表面活性剂种类及添加量合成NiO纳米粉体。结果表明：在微波加热160℃合成了片状纳米NiO前驱体，片层厚度约为10nm，经过400℃煅烧2h得到了具有微纳米多级结构的花片状NiO微球，微球直径约为2μm，花片状NiO的厚度为10nm。表面活性剂的添加使NiO微球团聚现象明显减弱，且使微球形状规则，尺寸均一。通过电化学测试表明，添加3.7%PEG-4000，保温30min条件下制备纳米NiO电极比电容最大为85.4F/g，经过500次循环后，比电容仅衰减13.3%，表现出较好的电化学稳定性。以泡沫镍为载体，分别以NiSO4和Ni(NO3)2·6H2O为镍源，通过改变镍离子浓度、表面活性剂种类和添加量、反应时间，采用微波水热原位负载的方法制备具有微纳米多级结构的NiO/泡沫镍复合电极材料样品。结果表明：以NiSO4为镍源合成的纳米NiO以花片状均匀原位生长在泡沫镍表面，表面活性剂PEG-4000的添加反而抑制了片状纳米NiO在泡沫镍上的生长。测试结果表明，保温30min，无添加剂条件制备的微纳米多级结构的NiO/泡沫镍样品电极获得的比电容可达到234.8F/g。以Ni(NO3)2·6H2O为镍源，保温60min合成了颗粒状纳米NiO并在泡沫镍表面均匀生长，表面活性剂PEG-4000的添加使纳米NiO贴附在泡沫镍表面，不利于离子和电子的传递。保温60min且无添加剂制备的NiO/泡沫镍样品电极比电容最大为224.4F/g。以活性碳纤维布（ACFC）为载体，以尿素和NiSO4为原料，采用微波水热法通过改变反应物浓度和反应时间得到不同的NiO/ACFC复合电极材料，并对样品电极进行了电化学特性研究。结果表明：实验合成的纳米NiO以花片状结构原位生长在活性碳纤维布表面，片层厚度约为10nm。在相同的微波合成条件下，表面活性剂PEI添加量和尿素量对样品形貌结构和负载量有较大影响。当镍离子与尿素摩尔比CNi2+:C(NH2)2CO为1:4，添加1ml PEI，保温60min的NiO/ACFC复合电极材料电极获得最大的比电容为190.4F/g，具有良好的电化学性能和稳定性能。
[Abstract]:Along with the global energy shortage and environmental deterioration, the electrochemical cycle device can be getting more and more attention. As a new type of super capacitor energy storage device, because of its high power density has the advantages of no pollution, long cycle, which attracted widespread attention and research. And its performance depends on the electrode the choice of materials. The metal oxides and carbon materials as the advantages and disadvantages of electrode material, metal oxide and nickel foam collector, carbon material load for preparing composite electrode material with good performance has become a prime target for material research scholars.
This paper adopts the microwave hydrothermal method, the nano nickel oxide preparation and the use of nickel foam or activated carbon fiber cloth as the carrier to load nano nickel oxide to obtain micro related problems of composite material with nano structure is studied by X, X-ray diffraction, thermal analysis, scanning electron microscopy, morphology and structure of testing technology the materials were characterized and observation, and through the cyclic voltammetry test on the electrochemical performance of as prepared electrode materials by AC impedance method. The main work includes the following aspects:
By microwave hydrothermal method, using NiSO4 as the source of nickel, urea as precipitant, respectively using polyethylene glycol 4000 (PEG-4000) and polyetherimide (PEI) as the surfactant, by changing the holding time, surfactant type and adding amount of NiO nano powders were synthesized. The results showed that the nano NiO precursor synthesis microwave heating at 160 DEG C, the lamellar thickness is about 10nm, after 400 2H calcined was obtained with micro nano hierarchical structure flower like NiO microspheres, the diameter is about 2 m, the thickness of the NiO flower like to add 10nm. surfactant NiO microspheres aggregation decreased significantly, and the shape of microspheres, uniform size. Through electrochemical tests show that the addition of 3.7%PEG-4000, the preparation of nano NiO electrode specific capacitance 85.4F/g maximum insulation under the condition of 30min, after 500 cycles, the specific capacitance decay is only 13.3%, showing good electrochemical stability.
With nickel foam as the carrier, respectively by NiSO4 and Ni (NO3) 2 - 6H2O as the source of nickel, nickel ions by changing the concentration of surfactant type and dosage, reaction time, using the method of load in situ microwave hydrothermal preparation with micro nano hierarchical structure of NiO/ foam nickel composite electrode material samples. Show that NiSO4 as the source of nickel nano NiO synthesized in situ growth on the surface of uniform flower like nickel foam, adding surfactant PEG-4000 inhibited the NiO nanosheets on nickel foam growth. The test results show that the thermal insulation 30min, NiO/ nickel foam electrode micro nano hierarchical additive preparation conditions the specific capacitance can reach 234.8F/g. to Ni (NO3) 2 - 6H2O as the source of nickel, 60min insulation granular nano NiO was synthesized and grown on nickel foam with uniform surface and surface active agent PEG-4000 is added into NiO nanoparticles attached on the surface of nickel foam, It is not conducive to the transfer of ions and electrons. The maximum specific capacitance of NiO/ foam nickel sample electrode prepared with 60min and no additives is 224.4F/g.
The activated carbon fiber cloth (ACFC) as the carrier, with urea and NiSO4 as raw materials, NiO/ACFC composite electrode materials by changing different reactant concentration and reaction time by microwave hydrothermal method, and the sample electrode were studied. The results showed that the electrochemical properties of nano NiO synthesized by in situ growth in flower like structure the activated carbon fiber cloth surface layer thickness is about 10nm. in microwave synthesis under the same conditions, surfactant dosage of PEI and urea content has a great influence on the morphology and structure of load. When the nickel ion and urea molar ratio of CNi2+: C (NH2) 2CO 1:4, adding 1ml PEI, NiO/ACFC composite electrode materials the maximum insulation 60min electrode specific capacitance is 190.4F/g with good electrochemical performance and stable performance.

【学位授予单位】：济南大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TM53

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