【作者】 付国瑞；

【导师】 胡中爱；

【作者基本信息】 西北师范大学 ， 物理化学， 2010， 硕士

【摘要】 电化学电容器是一种介于传统电容器和电池之间的重要的新型储能装置。电极是电化学电容器的重要组成元件，而电极材料又是构筑电极的重要组成部分。因此，具有优良电化学性能的电极材料的研发对电化学电容器的发展起着至关重要的作用。钴、镍氢氧化物及其氧化物电极材料因其具有良好的氧化还原反应活性和独特的结构而表现出优异的电化学性能，在电化学电容器电极材料的应用方面具有潜在价值。本论文概述了电化学电容器及其电极材料的研究进展，采用电沉积法制备出四种电极材料。利用现代分析测试手段对目标材料的形貌、晶型结构和组成等进行了分析表征，采用电化学测试方法对电极材料的电化学性能等进行了详细研究。主要内容概括如下：1.以镍箔为基底，在硝酸镍溶液中，用电沉积法制备了Ni（OH）₂薄膜。采用X射线衍射（XRD）和场发射扫描电子显微镜（FESEM）表征了产物的结构和形貌，XRD结果显示样品为典型的α相Ni（OH）₂。FESEM分析结果表明所得样品呈均匀疏松的颗粒状，其直径约为80⁹0 nm，进一步观察发现，这些疏松的颗粒是由粒径（约30⁴0 nm）更小的纳米粒子组成。用红外光谱（FT-IR）和热分析（TG-DTA）分别对所得样品的组分和热稳定性进行了表征；用循环伏安和恒电流充放电等电化学测试方法对其电化学性能进行了研究。此外，详细考察了电沉积条件对其电化学性能的影响。结果表明，所制得的α-Ni（OH）₂薄膜表现出优良的电化学电容性能，其单电极比电容值达2520 F·g^-1。2.将上述通过电沉积法制备出的Ni（OH）₂薄膜，进行热处理后转化为NiO薄膜电极材料。用X射线衍射（XRD）和场发射扫描电子显微镜（FESEM）表征了产物的结构和形貌；使用循环伏安法、恒电流充放电和交流阻抗等电化学方法系统研究了所制备样品的电化学性能。研究结果表明，在Ni（NO₃）₂溶液浓度为0.08 mol·L^-1，电压为-0.9 V条件下沉积，并经过250℃热处理制备的NiO薄膜材料属于立方结构，表现出良好的电化学性能，其单电极比电容值达1220 F·g^-1。3.在硝酸钴溶液中，通过电沉积法在镍箔基底上制备出了Co（OH）₂薄膜材料。用X射线衍射（XRD）和场发射扫描电子显微镜（FESEM）表征了产物的结构和形貌。采用红外光谱（FT-IR）对产物的组分进行了分析。所得样品的热稳定性通过热分析（TG-DTA）进行表征。使用循环伏安、恒电流充放电和电化学交流阻抗（EIS）等测试方法对其电化学性能进行了研究。此外，还研究了沉积电压、沉积电量对Co（OH）-2薄膜电极电容性能的影响。结果表明，所得样品展现出空间交错的纳米片网状形貌，属于六方晶相的β-Co（OH）-2，表现出优良的电化学性能，其单电极比电容值达1042 F·g^-1，并且在10 A·g^-1的大电流密度下循环500周后仍能保持约72%的初始容量。是一种具有潜在应用价值的电化学电容器电极材料。4.将上述通过电沉积法制备出的Co（OH）-2薄膜，进行热处理后转化为Co₃O₄薄膜。采用X射线衍射（XRD）、红外光谱（FT-IR）和场发射扫描电镜（FESEM）对产物的结构、组分和形貌进行了分析表征；使用循环伏安法和恒电流充放电等电化学测试方法对所制备的样品进行了系统的电化学性能研究。研究表明，在Co（NO₃）₂溶液浓度为0.05 mol·L^-1，电压为-1.0 V条件下沉积，并经250℃热处理制备的Co₃O₄薄膜样品呈空间交错的纳米片网状形貌，属于尖晶石型结构，Co₃O₄薄膜电极表现出良好的电化学性能，其单电极比电容值达413 F·g^-1，且具有良好的循环稳定性更多还原

【Abstract】 At present, electrochemical capacitor is one kind of important new energystorage equipment, which between conventional capacitors and battery. Electrode isan important component of electrochemical capacitor, and the electrode material is animportant part of building electrode. Therefor, the research and preparation ofelectrode materials with good electrochemical performance plays a vital role in thedevelopment of electrochemical capacitor. Cobalt/Nickel hydroxide and oxide have apotential application in the electrode materials of electrochemical capacitor due totheir excellent electrochemical properties resulting from the good redox reactionactivity and unique structure.The present work reviewed the electrochemical capacitors and their electrodematerials, and then prepared the four kinds of electrode materials by electrodepositiontechnique. Their morphologies, crystal structure and components were characterizedby means of modern analysis techniques. The capacitive behaviors of the resultantmaterials were also measured by electrochemical skills. The main content is asfollows:1. Nickel hydroxide film was prepared by electrodeposition on nickel foil inNi（NO₃）₂ aqueous solution for the electrode materials of electrochemical capacitors.The structure and morphology of products were characterized using X ray diffraction（XRD） and field emission scanning electron microscopy （FESEM）, respectively. Theexperimental results of XRD show that the products are typicalα-phase nickelhydroxide. The FESEM results reveal that the as-preparedα-Ni（OH）₂ displays aloosely packed structure assembled by the relatively bigger particles （90 nm）. Thefurther observations indicate that the big particles are composed of several smallnanoparticals （30-40 nm）. The component and thermal stability of the products arerespectively measured by FT-IR, thermogravimetry and differential thermal analysis（TG/DTA）. The electrochemical performances are investigated by cyclic voltammetry（CV） and galvanostatic charge-discharge technique in 1 mol·L^-1 KOH electrolyte. Theresults show that the product has excellent electrochemical performances and itsspecific capacitance value as single electrode is up to 2520 F·g^-1. Furthermore, the effect of deposition conditions such as deposition potential and concentration ofNi（NO₃）₂ solution on the electrochemical capacitance of the deposited Ni（OH）₂ filmsis discussed in detail.2. Nickel oxide thin film is prepared by thermally treating the above-mentionedNi（OH）₂ film at different temperature in air. The crystal structure and surfacemorphology of the thin film is characterized by X-ray diffraction （XRD） and fieldemission scanning electron microscopy （FESEM）, respectively. The electrochemicalperformance of the thin film electrode is also investigated using cyclic voltammetry,galvanostatic charge-discharge, and electrochemical impedance spectroscopy. NiOthin film, which is prepared by electrodeposition under the conditions of Ni（NO3）2solution concentration of 0.08 mol·L^-1 and potential of -0.9 V, and then thermallytreated at 250℃, is a typical cubic structure. The electrochemical test results show ithas good electrochemical performance. The single-electrode specific capacitancevalue is up to 1220 F·g^-1, and expected to as a promising electrode material ofelectrochemical capacitors.3. Cobalt hydroxide film was electrodeposited on nickel foil in Co（NO₃）₂aqueous solution. The structure and morphology of Co（OH）2 film were characterizedusing X-ray diffraction （XRD） and field emission scanning electron microscopy（FESEM）, respectively. The component and thermal stability of the sample weremeasured by FT-IR and thermal analyses, including thermogravimetry （TG） anddifferential thermal analysis （DTA）. The electrochemical performance wasinvestigated by cyclic voltammetry, constant current charge/discharge technique andelectrochemical impedance spectroscopy. Furthermore, the effects of the appliedpotential and the total electrical quantity during electrodeposition of cobalt hydroxidefilm on its specific capacitance were studied. The results show that the as-preparedmaterials areβ-Co（OH）2 with a uniform sheet-like network morphology and haveexcellent electrochemical performances. The specific capacitance as single electrodeis up to 1042 F·g^-1, and remains at about 72% of the initial value after 500 cycles at acurrent density of 10 A·g–1. So it is a promising electrode material for electrochemicalcapacitors.4. The Co3O4 film was prepared by thermally treating the above-mentioned Co（OH）₂ film at different temperature in air. The structure and morphology of theCo3O4 film were characterized using X-ray diffraction （XRD） and field emissionscanning electron microscopy （FESEM）, respectively. The electrochemical propertieswere also investigated using cyclic voltammetry and galvanostatic charge-discharge.Co₃O₄ thin film, which was prepared by electrodeposition under the conditions ofCo（NO₃）₂ solution concentration of 0.05 mol·L^-1 and potential of -1.0 V, andsubsequent thermally treated at 250℃, is a typical spinel structure. Theelectrochemical test results show it has good electrochemical performance, the singleelectrode specific capacitance value is up to 413 F·g^-1 and showing good cyclestability, expected to as a promising electrochemical capacitors electrode material.更多还原