碳纳米材料与复合材料超级电容器的特性研究

发布时间：2018-04-10 05:27

  本文选题：超级电容器　切入点：碳纳米管　出处：《电子科技大学》2014年硕士论文

【摘要】：超级电容器是一种新型的储能装置,已经成功的应用于军事、航天航空、电动汽车、电子通信、交通运输等领域。相比于蓄电池,它拥有更大的功率特性和更久的充放电循环次数,也具有比常规电容器更高的能量密度。本文对碳纳米管的制备和酸化回流处理进行细致的分析,选用二氧化锰和碳纳米管作为超级电容器的电极材料进行了研究,使用场发射扫描电镜和X-射线粉末衍射对材料进行了形貌和物相分析,通过循环伏安法和恒流充放电测试研究了电极材料的电化学性能。主要内容如下:1.利用混酸(盐酸于硝酸比例为3:1)对碳纳米管进行了酸化回流处理,通过观察其表征可以看出在混酸的强氧化性作用下,碳纳米管得到了一定程度的纯化,管束被切断和打开,提高了碳纳米管内外表面积的利用率,在90℃下酸化回流4h得到的比电容为17.57F/g,相比于未经处理的碳纳米管的比电容10.74F/g有较大程度的提高。2.运用水热法制备了不同晶型的二氧化锰纳米棒,并在不同反应时间和不同反应温度下进行了对比实验,结果显示以氯酸钾为氧化剂,硫酸锰为锰源,在150℃下反应16h得到的α型MnO2有得到了较好的晶化,其长度大约为为1um左右,直径为150nm,比电容为111.32F/g,有较好的循环使用特性;反应物为过硫酸铵和硫酸锰时,发现在160℃下反应15h得到的β型MnO2的长度为1.3um,直径为80-150nm,比电容为88.97F/g。3.对比不同制备方法比较了MnO2/CNT复合电极材料的电化学性能。通过微波等离子化学气相沉积在硅片上生长了碳纳米管薄膜,并在此基体上沉积了MnO2,在恒流充放电测试下复合电极的比电容为141.31F/g。使用液相共沉淀法制备了MnO2包覆碳纳米管结构的电极材料,测得其比电容为151.76F/g。采用水热法制备了酸化处理的碳纳米管和MnO2纳米棒的复合材料,观察形貌看出材料中含有明显的MnO2/CNTs复合共聚物结构,分析恒流充放电曲线得出复合材料比电容为158.43F/g,相比于未参杂CNTs的MnO2材料有明显的提高。
[Abstract]:Supercapacitor is a new type of energy storage device, which has been successfully used in military, aerospace, electric vehicles, electronic communications, transportation and other fields.Compared with batteries, it has higher power characteristics, longer charge and discharge cycles and higher energy density than conventional capacitors.In this paper, the preparation of carbon nanotubes and acidizing reflux treatment are analyzed in detail. Manganese dioxide and carbon nanotubes are selected as electrode materials for supercapacitors.Field emission scanning electron microscopy (SEM) and X-ray powder diffraction (XRD) were used to analyze the morphology and phase of the electrode. The electrochemical properties of the electrode were studied by cyclic voltammetry and constant current charge-discharge test.The main content is as follows: 1.Carbon nanotubes (CNTs) were treated by acidizing refluxing with mixed acid (the ratio of hydrochloric acid to nitric acid is 3: 1). By observing its characterization, it can be seen that under the strong oxidation of mixed acid, the CNTs were purified to a certain extent, and the tube bundles were cut off and opened.The internal and external surface area utilization of CNTs was improved. The specific capacitance obtained by acidizing reflux for 4 h at 90 鈩，

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