基于碳納米管復合材料的超級電容器研究
發(fā)布時間：2018-07-16 18:12
【摘要】：超級電容器因具備高比電容、高功率密度、綠色環(huán)保、循環(huán)壽命長等特點而受到全球科研工作者的廣泛關注。其中,工作電極是超級電容器的重點組成部分,而電極性能的好壞則由電極材料和制備工藝決定。本文從制備具有高比電容的電極材料出發(fā),分別運用不同方法制備了氧化錳、碳納米管/氧化錳、氧化鈷、碳納米管/氧化鈷電極材料,采用X射線衍射、電子掃描電鏡、X射線能譜儀等測試手段對材料成分進行了物相分析及表面形貌表征分析,通過計時電位法、循環(huán)伏安等測試方法討論分析了所制備材料作為超級電容器的電化學特性,主要工作內(nèi)容與結論如下:1、研究了溫度對MnSO4和KNO3熔鹽反應體系產(chǎn)物價態(tài)、晶體表面形貌以及電化學性能的影響。所制備出MnO2材料比Mn3O4材料的比電容高57.7%;在MnO2材料中加入CNTs能夠使MnO2材料的內(nèi)阻以及導電性能有所改善,測得的CNTs/MnO2復合電極的比電容為141.2F/g,比MnO2電極的比電容增加了51.5%。2、對水熱法不同溫度合成的材料進行了成分形貌分析與電化學性能測試,結果表明在一定溫度范圍內(nèi),隨著溫度的提升,晶化程度不斷提高,同等條件下水熱法于150℃制備的針狀MnO2比電容最高,達到97.7F/g;水熱法合成的CNTs/MnO2復合電極的比電容為181.2F/g,比MnO2比電容提高了85.5%,比熔鹽法制備的CNTs/MnO2復合電極比電容提高了28.3%。3、水熱法制備的Co3O4電極在三電極體系下以6mol/L的KOH為電解質在10mA/cm2電流密度下測得的比電容為93.5F/g;在Co3O4先驅體反應體系中加入CNTs和活化劑CTAB制備出的CNTs/Co3O4復合材料呈現(xiàn)包覆結構,分布均勻,空隙豐富,團聚現(xiàn)象減輕,在10mA/cm2電流密度下測得的比電容達179.1F/g,比Co3O4電極提高了91.5%。4、熔鹽法、水熱法制備的MnO2電極、Mn3O4電極以及CNTs/MnO2電極以Na2SO4為電解質,通過循環(huán)伏安測試表明其比電容主要通過吸附/脫附電子類型的贗電容來獲得,而水熱法合成的Co3O4電極和CNTs/Co3O4電極以KOH為電解質則主要是通過氧化還原反應類型的贗電容效應來獲得比電容。
[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，
本文編號：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，
本文編號：2127218
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