多形貌超薄镍钴基纳米复合物的制备及其超级电容器性能的研究

发布时间：2018-06-02 14:30

本文选题：超薄片状 + 镍钴基纳米复合材料　；参考：《吉林大学》2017年硕士论文

【摘要】：在文中,三维多孔的泡沫镍被选作基体,在合适的水热条件下原位生长不同形态和结构的镍钴基纳米复合材料。它们直接用作电极材料,避免粘结剂的使用,这极大地增强了活性物质的电化学活性。超薄片状镍钴基氢氧化物(Ni1Co2)通过一锅反应成功地生长到泡沫镍上制备。在反应中,不需要添加额外的碱源,利用硝酸盐中的NO_3~-离子释放OH~-离子,并且伴随着部分Co2+离子的氧化。制备的Ni1Co2展现出超薄的纳米片结构,片状Ni1Co2的厚度主要集中在5到13 nm之间。用于电化学测试,确保Ni1Co2复合物与电解质充分的接触和快速的电荷转移。在三电极体系测试中(3 M KOH电解质),自立式Ni1Co2电极片表现出超高的的比电容(在1 A g-1下2654.9 F g-1),良好的循环稳定性(在10 A g-1高电流密度下1500次循环后有着77%保留率)。为了进一步研究它的电化学性质,简单的非对称超级电容器(ASC)被设计,使用Ni1Co2纳米片作为正极和活性炭(AC)作为负电极,并记为Ni1Co2//AC。这个Ni1Co2//AC ASC拥有宽的电压窗口(0-1.6 V),呈现出优秀的42.4 W h kg-1的能量密度(功率密度为823.2 W kg-1)和仍然保留了24.8 W h kg-1(10170.8 W kg-1)。与此同时,ASC装置依然拥有良好的循环稳定性(5 A g-1的电流密度下循环3000次保留94%的容量)。钴掺杂氢氧化镍/三硫化二镍复合物(Ni Co-10)通过简易的一锅水热反应伴随两步控温的方式原位生长在泡沫镍,避免复杂的生产过程或高端技术的使用。有趣的是,Ni Co-10呈现出了一种独特一维仙人鞭状(1D SL)结构,其内部由超薄纳米片组成。我们选择反应的各个阶段(90加热4小时,90加热4小时随后110度加热5小时,90加热4小时随后110度加热10小时)进行对比,得出了整个转变过程。随着反应的进行,纳米片状结构逐渐向仙人鞭状转变,而生成物中钴元素含量也在逐渐增加。在水热条件下直接作为超级电容器,无粘结剂的Ni Co-10电极展现超高的比容量(在1 A g-1下3023.4 F g-1)和优秀的倍率性能(即使在20 A g-1下电容保留率可达82.9%),这些都归功于这种独特的开放的超薄仙人鞭状结构。同时,在组装非对称超级电容器过程中,其中Ni Co-10用作是正极,并用活性炭(AC)作为负极。这非对称的装置可以表现出高比电容值为136.2 F g-1(在1 A g-1的电流密度),高能量密度的51.5 W h kg-1(在0.825 k W kg-1的密度)和23.0 W h kg-1(即使在8.25 k W kg-1),和适当的循环稳定性。这些电极材料的制备过程简易,合成材料廉价、环保。不仅如此,这些制备电极材料在电化学测试中显示出高的能量储存、优异倍率性能和在电化学作用下较好的稳定性,这些优势使得它们能使其成为一个有前途的储能电极材料。
[Abstract]:In this paper, three dimensional porous nickel foam was selected as matrix, and different morphology and structure of nickel and cobalt matrix nanocomposites were grown in situ under suitable hydrothermal conditions. They are directly used as electrode materials to avoid the use of binders, which greatly enhance the electrochemical activity of active substances. Ultrathin nickel-cobalt hydroxide Ni _ 1Co _ 2) was prepared on foamed nickel by one-pot reaction. In the reaction, no additional alkali source is needed, and the NO3 + ion in the nitrate is used to release the OH- ion, which is accompanied by the oxidation of part of the Co2 ion. The prepared Ni1Co2 exhibits ultrathin nanochip structure, and the thickness of flake Ni1Co2 is mainly between 5 nm and 13 nm. For electrochemical testing to ensure adequate contact with electrolytes and rapid charge transfer of Ni1Co2 complexes. In the three-electrode system test, the self-supporting Ni1Co2 electrode showed high specific capacitance (2654.9 F g -1 at 1 A g ~ (-1) and good cycle stability (77% retention rate after 1500 cycles at high current density of 10 A g ~ (-1). In order to further study its electrochemical properties, a simple asymmetric supercapacitor was designed, using Ni1Co2 nanoparticles as positive electrode and activated carbon acid) as negative electrode, and denoted as Ni _ 1Co _ 2 / A _ c. The Ni1Co2//AC ASC has a wide voltage window of 0-1.6 V ~ (-1), showing excellent energy density (power density of 823.2 W 路kg ~ (-1) of 42.4 W / h kg-1 and still retaining 24.8 W / h kg-1(10170.8 W 路kg ~ (-1). At the same time, the ASC device still has good cycle stability at the current density of 5 A g ~ (-1). It retains 94% capacity at 3000 times. Co-doped nickel hydroxide / nickel trisulfide (Ni Co-10) is grown in situ by a simple one-pot hydrothermal reaction with two-step temperature control to avoid complex production processes or the use of high-end technology. It is interesting to note that the Ni Co-10 exhibits a unique one-dimensional whiplash 1D structure, which is made up of ultrathin nanocrystals. We chose each stage of the reaction to be heated for 4 hours and 90 for 4 hours and then 110 degrees for 5 hours and 90 for 4 hours and then 110 degrees for 10 hours. With the development of the reaction, the nanoscale structure gradually changed to the whiplash shape, and the content of cobalt in the product increased gradually. As supercapacitors directly under hydrothermal conditions, The binderless Ni Co-10 electrode exhibits high specific capacity (3023.4 F g -1 at 1 A g -1) and excellent rate performance (even at 20 A g -1 the capacitance retention rate can reach 82.9%), which is due to this unique open and ultra-thin bullwhip structure. At the same time, in the process of assembling asymmetric supercapacitors, Ni Co-10 is used as positive electrode and AC as negative electrode. The asymmetric apparatus can show a high specific capacitance of 136.2 F g -1 (current density at 1 A g -1), a high energy density of 51 5 W kg-1 (at 0.825 kW kg-1) and a 23.0 W kg -1 (even at 8 25 kg -1 g -1), and appropriate cyclic stability. The preparation of these electrode materials is simple, cheap and environmentally friendly. Moreover, these prepared electrode materials show high energy storage, excellent rate performance and good stability under electrochemical action in electrochemical testing. These advantages make them a promising electrode material for energy storage.
【学位授予单位】：吉林大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TB383.1;TM53

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