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1、湘潭大学硕士学位论文超级电容器用活性炭/氢氧化镍复合材料电化学性能研究姓名：黄庆华申请学位级别：硕士专业：物理化学指导教师：王先友20070501超级电容器用活性炭/氢氧化镍复合材料电化学性能研究 V 摘 要 超级电容器是一种介于电池与传统静电容器之间的新概念能量储存器件，与传统静电容器相比，超级电容器具有更高的能量密度，与电池相比，超级电容器具有更大的功率密度，从而具有瞬间释放特大电流的特性并且充放电效率高、循环寿命长。由于这些特性使得该器件具有某些特殊功能，其中特别为人关注的是在电动车辆、高功率武器等方面的不可替代的作用，另外可用作电子设备中的备用电源、工业设备的闪光及点火装置。由于超级电
2、容器具有广阔的应用前景，开展超级电容器电极材料、电解液等应用基础研究，对电子工业和电动汽车的发展都具有重要意义。 本文以活性炭（AC）为基体，用 2 mol/L 不同的溶液（氯化锌、磷酸和硝酸）分别对其进行活化处理得到活性炭电极材料，用 X-射线衍射（XRD） 、孔结构分析（BET） 、循环伏安（CV）和恒流充放电等一系列测试技术进行研究。结果表明硝酸活化处理后的活性炭具有较好的电化学性能，该活性炭材料具有比表面积高达 2514 m2/g，孔径分布主要以微孔和孔径较小的中孔为主，平均孔径为 2.13 nm；将其制成的活性炭电极在 6 mol/L KOH 电解液中不同的电位窗口下都具有良好的电化
3、学性能；当扫描速度为 2 mV/s 时，电位窗口为-10 V 时，活性炭电极的比电容高达 255.1 F/g；将其制成的活性炭超级电容器具有较好的充放电性能，比电容为 61.3 F/g。 用化学沉淀法往活性炭（AC）材料中掺入少量氢氧化镍，制得氢氧化镍/AC复合材料，并探讨了氢氧化镍的最佳掺入量及复合材料的电化学性能。XRD 结果表明所得复合材料为 -Ni(OH)2/活性炭复合材料，其比表面积和孔容较原活性炭材料均有一定程度的减小，但复合材料仍然具有较高的比表面积和孔容。对不同氢氧化镍负载量的复合电极在 6 mol/L KOH 溶液中进行循环伏安测试结果表明，复合材料均表现出良好的电容行为；氢
4、氧化镍最佳负载量为 6 wt.%，对应的复合电极的比电容最大，高达 314.5 F/g，比原活性炭电极提高了 23.3%。 将复合材料制成对称型电容器进行电化学测试，结果表明：氢氧化镍/AC 复合材料更好地利用了双电层电容和法拉第准电容，表现出相对活性炭材料更好的电化学性能， 具有较小的阻抗性能、 较小的漏电流和更长的循环寿命。 氢氧化镍/AC复合材料对称型超级电容器具有较好的可逆性和充放电性能， 比电容高达 77.3F/g，相对活性炭超级电容器（61.3 F/g）提高了 26.1%。 同时，以氢氧化镍/AC 复合材料为正极，活性炭材料为负极制成了不对称型电容器，充放电结果表明它在 6 mol
5、/L KOH 溶液中比电容达到 84.7 F/g，高于复合超级电容器用活性炭/氢氧化镍复合材料电化学性能研究 VI材料对称型电容器，且相对于原活性炭电容器（61.3 F/g）提高了 38.2%，并具有更好的功率特性。 关键词：超级电容器；活性炭；氢氧化镍；复合材料；对称型电容器；不对称型电容器；电化学性能 超级电容器用活性炭/氢氧化镍复合材料电化学性能研究 VIIABSTRACT The supercapacitor is a new type of electrochemical energy storage devices between the typical rechargeable
6、batteries and the typical dielectric capacitors and has advantages of both of them. The typical dielectric capacitors can provide high power densities and have very long cycle life, but they have low energy densities. The typical rechargeable batteries can provide high energy densities, but have low
7、 power densities and short cycling life. Supercapacitors can meet both the power and the energy requirements for such systems as acceleration power for electric vehicles, burst power for the generation of electronic devices and so on, and have drawn more and more attention in recent years. Because o
8、f their wide application foreground, its of great importance to conduct a series of experiments researching on electrode materials, electrolytes related techniques on supercapacitor, which can promote the development of the electronics industry and electric vehicles in our nation. In this thesis, a
9、new active carbon material used for double-layer capacitor was obtained by means of immersing the raw material in different solutions. The materials have been physically and chemically characterized by X-ray diffraction (XRD), BET, cyclic voltammetry (CV) and galvanostatic charge/discharge measureme
10、nt. The results show that the activated carbon (AC) obtained from 2 mol/L nitric acid imersinig has better electrochemical properties. Moreover, it has large surface area, up to 2514 m2/g; and most pores inside were micropores and mesopores with an average pore size of 2.13 nm. The activated carbon
11、electrodes show good electrochemical performance during different potential windows in 6 mol/L KOH electrolyte; its specific capacitance is up to 255.1F/g at a scan rate of 2 mV/s in the potential window of -1.00 V. Furthermore, the specific capacitance of AC supercapacitor is 61.3 F/g. In this pape
12、r, nickel hydroxide/activated carbon (AC) composite electrode for the electrochemical capacitor was prepared by a simple chemical precipitation method. The structure and morphology of nickel hydroxide/AC were characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM). The result
13、s show that nano-sized nickel hydroxide was loading into the surface of activated carbon. Electrochemical performance of the composite electrodes with different loading amount was studied by cyclic voltammetry and galvanostatic charge/discharge measurement. The optimal loading amount of nickel hydro
14、xide is 6 wt.%. It demonstrates that the introduction of small amount nickel hydroxide on activated 超级电容器用活性炭/氢氧化镍复合材料电化学性能研究 VIIIcarbon could promote the specific capacitance of composite electrode. The composite electrodes have good electrochemical performance and high charge-discharge properties.
15、 When the loading amount of nickel hydroxide is 6 wt.%, the composite electrode shows a highest specific capacitance of 314.5 F/g, which has increased by 23.3% compared with pure activated carbon (255.1 F/g). A symmetrical capacitor was fabricated by the composite electrodes. Results show that the c
16、omposite electrochemical capacitor exhibits a stable electrochemical properties and a good reversibility in the potential range of 01.0 V. Its specific capacitance is up to 77.3 F/g, which has increased by 26.1% and means a good combination of double layer capacitance and faradaic pseudocapacitance. A hybrid supercapacitor was fabricated using a nickel hydroxide/AC composite positive electrode and an activated carbon negative electrode. The capacitance of AC superc
