过渡金属氧化物电化学电容器电极材料的制备、表征及性能测试

发布时间：2019-05-20 17:09

【摘要】：随着科技与社会的不断发展，能源问题越来越受到了广泛关注。电化学电容器作为一种储能器件具有较高的功率密度，较长的循环寿命，近年来受到了较多的关注。电化学电容器可以作为电池的补充器件，克服了电池功率密度低无法短时间释放大量能量的缺点，从而进一步拓宽了电能的应用领域。根据储电机理，电化学电容器可分为双电层电容器和赝电容电容器，本文主要研究了赝电容电容器电极材料中的过渡金属氧化物电极材料的制备，表征和测试，本文中包含的主要工作包括：（1）以Ag纳米线和高锰酸钾溶液为原料，通过水热法在pH为7.00和pH为0.76的溶液中制备了不同形貌的Ag/MnOx一维纳米结构并研究结构。通过XRD，TEM，SEM，BET等表征技术，发现在中性条件下，得到的Ag/MnOx复合材料为直径在160nm左右，内径在120nm左右的一维纳米管状结构，由中空Ag纳米管和包覆于其上的非晶MnO2组成，，经测量可知，该结构的比表面积为26m2/g；在酸性环境下，得到的Ag/MnOx复合材料是由纳米片组成的直径为490nm的一维多层纳米结构,其比表面积为108m2/g。本文在三电极体系中对两种结构的材料的电化学性能进行了测试，可知一维纳米管状结构和一维多层纳米结构和在0.1A/g的电流密度下分别得到了135F/g和180F/g的电化学性能；在5A/g的电流密度下分别保持了20F/g和130F/g。在随后的循环测试中，两种材料在1A/g的电流密度下循环1000次后，均保持80%以上的初始比电容，具有较为广阔的应用前景。（2）以Co(NO3)2，Ni(NO3)2和NH4NO3为原材料，通过电沉积法在泡沫镍上沉积了绿色(Co, Ni)氢氧化物前驱体，并通过退火处理制备了NiCo2O4纳米电极材料。本文中研究了不同沉积时间和不同沉积浓度对于NiCo2O4电极材料的形貌的影响以及电沉积过程中材料的生长机制。通过SEM和TEM表征发现在不同的沉积条件下生长在泡沫镍上的NiCo2O4电极材料由一层厚度为0.78μm-6.80μm不等的沉积层和长度为56nm-1100nm不等的纳米片组成的。通过观察相同浓度不同沉积时间的实验样品可发现，沉积层的厚度随沉积时间的延长变厚，而纳米片的长度则先增加后变短。本文通过对这些样品进行恒流密度充放电以及循环伏安测试找出了最佳的沉积条件，在该条件下得到的样品沉积层的厚度为5.36μm，纳米片长度为600-1100nm。该电极材料在1mA/cm2的充放电电流密度下比容量达到了2.34F/cm2，在15mA/cm2电流密度下比容量依然保持了1.00F/cm2。该样品在5mA/cm2的充放电电流密度下循环充放电4000次之后依然保持了70%的初始比容量，显示出了较高的循环稳定性。
[Abstract]:With the development of science and technology and society, the energy problem is getting more and more attention. As a kind of energy storage device, the electrochemical capacitor has higher power density and longer cycle life, and has received much attention in recent years. The electrochemical capacitor can be used as a supplementary device of the battery, and overcomes the defect that the battery power density is low and a large amount of energy cannot be released in a short time, so that the application field of electric energy is further widened. According to the electric storage mechanism, the electrochemical capacitor can be divided into electric double layer capacitor and pseudo-capacitor, and the preparation, characterization and test of the transition metal oxide electrode material in the electrode material of the pseudo-capacitor are mainly studied. The main work included in this paper is as follows: (1) Ag/ MnOx one-dimensional nanostructures with different morphology were prepared by hydrothermal method in a solution with a pH of 7.00 and a pH of 0.76 by using an Ag nano-wire and a potassium permanganate solution as raw materials, and the junction The Ag/ MnOx composite material obtained by XRD, TEM, SEM, BET and the like was found to be a one-dimensional nano tubular structure with a diameter of about 160 nm and an inner diameter of about 120 nm. It is known that the specific surface area of the structure is 26 m2/ g; in the acidic environment, the obtained Ag/ MnOx composite material is a one-dimensional multi-layer nano-structure with a diameter of 490 nm, which is 108 m2/ g, G. The electrochemical performance of the materials of the two structures was tested in the three-electrode system. It was found that the one-dimensional nano-tubular structure and one-dimensional multilayer nano-structure and the electrochemical performance of 135F/ g and 180F/ g were obtained at the current density of 0.1 A/ g, respectively, and 20 F/ g and 130 F/ g were maintained at the current density of 5 A/ g, respectively. g. in the subsequent cycle test, the two materials are circulated for 1000 times under the current density of 1 A/ g, the initial specific capacitance of more than 80% is maintained, and the two materials have a wide application (2) Co (NO3)2, Ni (NO3)2 and NH4NO3 are used as raw materials, and a green (Co, Ni) hydroxide precursor is deposited on the foam nickel by an electrodeposition method, and the NiCo2O4 nano-electricity is prepared by the annealing treatment. The effect of different deposition time and different deposition concentration on the morphology of NiCo2O4 electrode materials and the life of materials during electrodeposition are studied in this paper. The long-term mechanism is characterized in that the NiCo2O4 electrode material grown on the foam nickel under different deposition conditions is characterized in that the NiCo2O4 electrode material which is grown on the foam nickel under different deposition conditions is composed of a deposition layer with a thickness of 0.78 & mu; m-6.80 & mu; m and a nano sheet with a length of 56nm-1100nm The experimental samples with different deposition times at the same concentration can be found, the thickness of the deposited layer becomes thicker with the increase of the deposition time, and the length of the nanosheet is increased first The optimum deposition conditions were found by the constant current density charge and discharge of these samples and the cyclic voltammetry. The thickness of the sample deposited layer under this condition was 5.36. m u.m, and the length of the nanosheet was 600-110. The electrode material has a specific capacity of 2.34 F/ cm2 at a charge/ discharge current density of 1 mA/ cm2 and a specific capacity of 1.00F/ cm2 at a current density of 15 mA/ cm2 Cm2. The sample has been charged and discharged at a charge/ discharge current density of 5 mA/ cm2 for 4000 times, and the initial specific capacity of 70% is still maintained, showing a higher cycle.
【学位授予单位】：北京工业大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TM53

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