镍基复合纳米材料的合成及其在超级电容器中的应用

发布时间：2018-02-27 09:44

本文关键词： 超级电容器水热法复合材料锰酸镍钴镍双氢氧化物镍钴氢氧化物与钼氧化物　出处：《西南大学》2017年硕士论文　论文类型：学位论文

【摘要】：超级电容器是介于电池和传统电容器之间的一种高效、环保、新型的电化学能量储存元件,拥有高功率密度、长使用寿命和大电流快速充电等优势,在很多领域具有无与伦比的发展空间和实用价值。在超级电容器电极材料研究中,我们发现廉价金属氧化物/氢氧化物由于优秀的电化学性质、原料丰富便宜、环保等,已成为近年来科技工作者的研究热点。本论文以镍、钴、钼以及锰为原料制备合成了二元或三元金属氧化物复合材料,以解决金属氧化物电极材料的低电导率、循环稳定性差等问题。且比较系统的探索了合成条件、材料复合对电极材料的形貌、结构和电学性能的影响。研宄成果如下:(1)通过水热法,以硝酸镍和氯化锰为原料,在碳布基底上生长了具有高比电容的二维纳米片结构的NiMnO3复合材料。利用XRD和SAED观察并研究了样品的物相组成;利用SEM和TEM系统的研究了材料的形貌和结构;用CHI660e对其电学性质进行了大量的测试。结果显示,NiMnO3拥有比较大的容量、大电流倍率特性。其中,Ni/Mn摩尔比3:3且在6h水热条件下合成的NiMnO3复合材料拥有较高的比容值,最高能有2330F/g(1A/g),20A/g电流密度下的比电容为1640F/g,比电容的保持率为70.3%,但NiMnO3材料连续充放电1000次后剩余比容值是最初比容值的67.2%,说明NiMnO3具有较低的循环性能。(2)通过水热法,以硝酸钴、硝酸镍为原料,在碳布基底上生长了二维纳米片结构的Co-Ni层状双氢氧化物(LDH)复合材料。利用XRD和SAED观察并研究了样品的物相组成;利用SEM和TEM系统的研究了材料的形貌和结构;用CHI660e对其电学性质进行了大量的测试。按照测试结果能够得出,Co-Ni LDH电极材料拥有较大的电容、大电流倍率性能。其中,Co/Ni摩尔比1:3且在6h水热条件下合成的Co-Ni LDH拥有较高的比容量,高达2766F/g(1A/g),20A/g电流密度下的比电容为2360F/g,比电容的保持率为85.3%,并且连续充放电1000次后剩余比容值是最初比容值的77.2%。基于以上实验结果,钴、镍价格便宜、合成方法简单以及高的比电容等优势,我们认为Co-Ni LDH复合材料具有很高的应用价值以及具有很好的发展空间。(3)通过水热法,以硝酸钴、硝酸镍和钼酸钠为原料,在碳布基底上生长了二维纳米片结构的镍钴氢氧化物与钼氧化物复合材料。利用XRD和SAED观察并研究了样品的物相组成;利用SEM和TEM系统的研究了材料的形貌和结构;用CHI660e对其电学性质进行了大量的测试。结果显示,镍钴氢氧化物与钼氧化物复合材料的比量容较大,拥有大电流倍率性能和优秀的稳定性能。镍钴氢氧化物与钼氧化物复合材料的比容量有2562F/g(1A/g),10A/g电流密度下的比电容为2260F/g,比电容的保持率为88%,且镍钴氢氧化物与钼氧化物复合材料连续充放电1000次后其比电容衰减仅为9%,从而表明镍钴氢氧化物与钼氧化物是最有发展潜力的电极材料。
[Abstract]:Supercapacitor is a kind of high efficiency, environmental protection, new electrochemical energy storage element between battery and traditional capacitor. It has the advantages of high power density, long service life and fast charging with high current. In the study of electrode materials for supercapacitors, we have found that cheap metal oxides / hydroxides are cheap because of their excellent electrochemical properties, rich in raw materials and cheap, environmentally friendly, etc. In this paper, binary or ternary metal oxide composites were prepared from nickel, cobalt, molybdenum and manganese to solve the low conductivity of metal oxide electrode materials. The effects of synthesis conditions and composite materials on the morphology, structure and electrical properties of electrode materials have been systematically explored. The results are as follows: 1) by hydrothermal method, nickel nitrate and manganese chloride are used as raw materials. NiMnO3 composites with high specific capacitance were grown on the carbon cloth substrate. The phase compositions of the samples were observed and studied by XRD and SAED, and the morphology and structure of the samples were studied by SEM and TEM systems. A large number of electrical properties have been tested by CHI660e. The results show that NiMnO3 has a relatively large capacity and high current rate. The NiMnO3 composites synthesized at the molar ratio of 3: 3 and 6 h hydrothermal condition have a higher specific volume value. The maximum specific capacitance of 2330F / g / g 20A / g current density is 1640Fr / g, and the specific capacitance retention rate is 70.30.But the residual specific capacitance of NiMnO3 material is 67.2% of the initial specific volume value after 1, 000 continuous charging and discharging, indicating that NiMnO3 has lower cycling performance. 2) by hydrothermal method, cobalt nitrate, Two-dimensional nanostructured Co-Ni layered double hydroxide (Co-Ni) composite was grown on carbon cloth substrate with nickel nitrate as raw material. The phase composition of the sample was observed and studied by XRD and SAED, and the morphology and structure of the material were studied by SEM and TEM system. A large number of electrical properties have been tested by CHI660e. According to the test results, it can be concluded that the Co-Ni LDH electrode material has a large capacitance. The Co-Ni LDH synthesized at 6 h hydrothermal condition has high specific capacity, and the molar ratio of Co / Ni is 1: 3, and the ratio of Co / Ni is 1: 3, and the LDH synthesized at 6 h hydrothermal condition has a high specific capacity. The specific capacitance is 2360 F / g at current density up to 2766 F / g / g, the specific capacitance retention is 85.3%, and the residual specific capacitance is 77.2% of the initial specific volume value after 1000 continuous charging and discharging. Based on the above experimental results, cobalt and nickel are cheap. The synthesis method is simple and has the advantages of high specific capacitance. We think that Co-Ni LDH composites have high application value and good development space. Through hydrothermal method, cobalt nitrate, nickel nitrate and sodium molybdate are used as raw materials. Ni-Co hydroxide and molybdenum oxide composites with two-dimensional nanostructures were grown on the carbon cloth substrate. The phase composition of the samples was observed and studied by XRD and SAED, and the morphology and structure of the samples were studied by SEM and TEM systems. A large number of electrical properties were tested by CHI660e. The results showed that the specific capacity of Ni-Co hydroxide / molybdenum oxide composite was larger. The specific capacity of Ni-Co hydroxide / molybdenum oxide composite is 2562F / g / g, the specific capacitance is 2260Fr / g, the retention of specific capacitance is 88F / g, and the nickel cobalt hydroxide and molybdenum oxide have a specific capacity of 2562F / g / g / g current density, and the specific capacity of Ni-Co hydroxide / molybdenum oxide composite is 88%, and the specific capacity of Ni-Co hydroxide / molybdenum oxide composite is 2562F / g / g. The specific capacitance attenuation of the composite is only 9 after 1000 continuous charging and discharging, which indicates that nickel cobalt hydroxide and molybdenum oxide are the most promising electrode materials.
【学位授予单位】：西南大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TB33;TM53

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