基于碳纳米管复合材料的超级电容器研究
发布时间：2018-07-16 18:12
【摘要】：超级电容器因具备高比电容、高功率密度、绿色环保、循环寿命长等特点而受到全球科研工作者的广泛关注。其中,工作电极是超级电容器的重点组成部分,而电极性能的好坏则由电极材料和制备工艺决定。本文从制备具有高比电容的电极材料出发,分别运用不同方法制备了氧化锰、碳纳米管/氧化锰、氧化钴、碳纳米管/氧化钴电极材料,采用X射线衍射、电子扫描电镜、X射线能谱仪等测试手段对材料成分进行了物相分析及表面形貌表征分析,通过计时电位法、循环伏安等测试方法讨论分析了所制备材料作为超级电容器的电化学特性,主要工作内容与结论如下:1、研究了温度对MnSO4和KNO3熔盐反应体系产物价态、晶体表面形貌以及电化学性能的影响。所制备出MnO2材料比Mn3O4材料的比电容高57.7%;在MnO2材料中加入CNTs能够使MnO2材料的内阻以及导电性能有所改善,测得的CNTs/MnO2复合电极的比电容为141.2F/g,比MnO2电极的比电容增加了51.5%。2、对水热法不同温度合成的材料进行了成分形貌分析与电化学性能测试,结果表明在一定温度范围内,随着温度的提升,晶化程度不断提高,同等条件下水热法于150℃制备的针状MnO2比电容最高,达到97.7F/g;水热法合成的CNTs/MnO2复合电极的比电容为181.2F/g,比MnO2比电容提高了85.5%,比熔盐法制备的CNTs/MnO2复合电极比电容提高了28.3%。3、水热法制备的Co3O4电极在三电极体系下以6mol/L的KOH为电解质在10mA/cm2电流密度下测得的比电容为93.5F/g;在Co3O4先驱体反应体系中加入CNTs和活化剂CTAB制备出的CNTs/Co3O4复合材料呈现包覆结构,分布均匀,空隙丰富,团聚现象减轻,在10mA/cm2电流密度下测得的比电容达179.1F/g,比Co3O4电极提高了91.5%。4、熔盐法、水热法制备的MnO2电极、Mn3O4电极以及CNTs/MnO2电极以Na2SO4为电解质,通过循环伏安测试表明其比电容主要通过吸附/脱附电子类型的赝电容来获得,而水热法合成的Co3O4电极和CNTs/Co3O4电极以KOH为电解质则主要是通过氧化还原反应类型的赝电容效应来获得比电容。
[Abstract]:Supercapacitors with high specific capacitance, high power density, green environmental protection, long cycle life and so on have been widely concerned by researchers all over the world. The working electrode is the key part of the supercapacitor, and the electrode performance is determined by the electrode material and the preparation process. In this paper, manganese oxide, carbon nanotube / manganese oxide, cobalt oxide, carbon nanotube / cobalt oxide electrode materials were prepared by X-ray diffraction from electrode materials with high specific capacitance. The phase analysis and surface morphology analysis of the material were carried out by means of electron scanning electron microscope (SEM) and X-ray energy spectrometer (EDS), and the method of chronopotentiometry was used. The electrochemical characteristics of the prepared materials as supercapacitors are discussed and analyzed by cyclic voltammetry. The main work and conclusions are as follows: 1. The valence states of the products in the reaction system of MnSO4 and KNO3 are studied. The effect of crystal surface morphology and electrochemical properties. The specific capacitance of MnO2 material is 57.7 higher than that of Mn3O4 material, and the internal resistance and conductivity of MnO2 material can be improved by adding CNTs to MnO2 material. The measured specific capacitance of CNTs / MnO2 composite electrode is 141.2 F / g, and the specific capacitance of MNO _ 2 electrode increases by 51.5. 2. The composition morphology analysis and electrochemical performance test of materials synthesized by hydrothermal method at different temperatures have been carried out. The results show that the specific capacitance of CNTs / MNO _ 2 composite electrode is 141.2 F / g, and the specific capacitance is 51.5% higher than that of MnO2 electrode. With the increase of temperature, the degree of crystallization increases continuously. The specific capacitance of acicular MnO2 prepared at 150 鈩，
本文编号：2127218
[Abstract]:Supercapacitors with high specific capacitance, high power density, green environmental protection, long cycle life and so on have been widely concerned by researchers all over the world. The working electrode is the key part of the supercapacitor, and the electrode performance is determined by the electrode material and the preparation process. In this paper, manganese oxide, carbon nanotube / manganese oxide, cobalt oxide, carbon nanotube / cobalt oxide electrode materials were prepared by X-ray diffraction from electrode materials with high specific capacitance. The phase analysis and surface morphology analysis of the material were carried out by means of electron scanning electron microscope (SEM) and X-ray energy spectrometer (EDS), and the method of chronopotentiometry was used. The electrochemical characteristics of the prepared materials as supercapacitors are discussed and analyzed by cyclic voltammetry. The main work and conclusions are as follows: 1. The valence states of the products in the reaction system of MnSO4 and KNO3 are studied. The effect of crystal surface morphology and electrochemical properties. The specific capacitance of MnO2 material is 57.7 higher than that of Mn3O4 material, and the internal resistance and conductivity of MnO2 material can be improved by adding CNTs to MnO2 material. The measured specific capacitance of CNTs / MnO2 composite electrode is 141.2 F / g, and the specific capacitance of MNO _ 2 electrode increases by 51.5. 2. The composition morphology analysis and electrochemical performance test of materials synthesized by hydrothermal method at different temperatures have been carried out. The results show that the specific capacitance of CNTs / MNO _ 2 composite electrode is 141.2 F / g, and the specific capacitance is 51.5% higher than that of MnO2 electrode. With the increase of temperature, the degree of crystallization increases continuously. The specific capacitance of acicular MnO2 prepared at 150 鈩，
本文编号：2127218
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