锰系三元复合电极材料的制备及其电化学性能研究

发布时间：2018-05-05 10:48

本文选题：超级电容器 + MnO_2　；参考：《江苏大学》2017年硕士论文

【摘要】：随着传统能源带来的环境问题日益加剧,绿色环保的新型能源成为研究的热点,于是,能效高无污染的超级电容器应运而生,成为一种被广泛应用的储能设备。电极材料的性质对超级电容器性能起决定性作用。因此,开发具有能量密度高、倍率性能好等优越性能的电极材料已成为了研究的方向。本文以锰系金属氧化物(MnO_2、MnCo2O4.5)为基础,用简单的方法制备了其与过渡金属氧化物(Co_3O_4)、碳基材料(石墨烯,Graphene)、导电聚合物(聚吡咯,PPy;聚苯胺,PANI)以及金属有机骨架(MOFs)的三元复合材料并研究了其电化学性能,本课题主要开展的工作如下:(1)以改进Hummers法制备的氧化石墨烯(GO)作为模板,用化学原位氧化聚合法结合水热法合成了PPy/Graphene/MnO_2,通过各种手段对该复合材料的形貌和结构进行了表征,通过循环伏安(CV)、计时电位(GCD)、交流阻抗(EIS)等技术探究了其容量、倍率、循环稳定性等电化学性能。结果显示,PPy/Graphene/MnO_2复合材料克服了PPy循环稳定性不好,Graphene容量不高以及MnO_2导电性较差等不足之处,在1 A·g-1电流密度下,表现出492.56 F·g-1的相对较大的比电容。(2)通过简单的水热法和电化学沉积法设计合成了一种具有核-核-壳异质结构的Co_3O_4/PANI/Mn O2,通过XRD、SEM以及TEM等表征手段对其形貌和结构进行测试,通过CV、GCD、EIS等技术对其电化学性能进行了研究。结果证明,这种具有异质结构的复合材料利用个体的协同效应,在10 A·g-1大电流密度下,展现出1686.7 F·g-1的超高比电容以及充放电1000个循环之后,高达114.9%的容量保持率,为核壳结构电极材料的发展和理想超级电容器的构建开拓了思路。(3)以金属有机骨架ZIF-67为模板,通过离子共沉淀原理合成了具有空心多面体结构的Co_3O_4@NiCo_2O_4@MnCo_2O_(4.5)三元金属氧化物复合材料,通过XRD、SEM、EDS、TEM、XPS、FTIR以及BET等方法对这种具有特殊结构的纳米材料进行系统的表征,通过CV、GCD、EIS等技术研究了其容量、倍率、循环稳定性等电化学性能。结果表明,在10 A·g-1大电流密度下,该复合材料仍有1060F·g-1的较大容量,充放电1000个循环之后,容量保持率高达98.1%,说明其循环稳定性较好,是一种理想的超级电容器电极材料。
[Abstract]:With the increasing environmental problems brought by traditional energy, new energy sources of green and environmental protection have become the focus of research. Therefore, supercapacitors with high energy efficiency and no pollution have emerged as a kind of widely used energy storage equipment. The properties of electrode materials play a decisive role in the performance of supercapacitors. Therefore, the development of electrode materials with high energy density and good rate performance has become the research direction. This paper is based on the manganese metal oxide, MNO _ 2 and MnCo _ 2O _ 4. The ternary composites with transition metal oxide Co3O _ 4, carbon-based materials (graphene Graphenen, conducting polymer (polypyrrole PPyrite; Polyaniline Panni) and metal-organic skeleton (MOFs) were prepared by a simple method and their electrochemical properties were studied. The main work of this paper is as follows: (1) PPyR / Graphene / MNO _ 2 was synthesized by chemical in-situ oxidation polymerization combined with hydrothermal method, and the morphology and structure of the composite were characterized by various methods, using the modified Hummers method to prepare graphene oxide (GOO) as a template. The electrochemical properties of cyclic voltammetry (CV), chronopotentiometry (GCD) and AC impedance spectroscopy (EIS) were investigated by means of cyclic voltammetry (CV), cyclic voltammetry (CV), cyclic stability and so on. The results show that the PIP / Graphene / MNO _ 2 composite overcomes the disadvantages of poor cyclic stability of PPy and poor MnO_2 conductivity. At 1 A g ~ (-1) current density, A kind of Co_3O_4/PANI/Mn O _ 2 with core-shell heterostructure was designed and synthesized by simple hydrothermal method and electrochemical deposition method. The morphology and structure of Co_3O_4/PANI/Mn O _ 2 with core-shell heterostructure were measured by means of XRD-SEM and TEM. The electrochemical performance was studied by CVGCD-EIS and other techniques. The results show that the composite with heterogeneous structure exhibits an ultra-high specific capacitance of 1686.7 F g ~ (-1) and a capacity retention rate of 114.9% after charging and discharging 1000 cycles at a high current density of 10 A g ~ (-1), using the synergistic effect of individual. For the development of core-shell structure electrode materials and the construction of ideal supercapacitors, the idea of developing core-shell structure electrode materials and the construction of ideal supercapacitors has been developed. Based on the metal-organic skeleton ZIF-67 as the template, the Co3O structure Co _ 3O _ 2O _ 4mn Co _ 2O _ 2O _ 2 composite with hollow polyhedron structure has been synthesized through the principle of ion coprecipitation. The nano-materials with special structure were systematically characterized by means of XRDD-SEMC-EDS-TEMP-FTIR and BET. The electrochemical properties such as capacity, ratio, cyclic stability and so on were studied by CVGCD-EIS. The results show that the composite still has a large capacity of 1060F g ~ (-1) under the high current density of 10A g ~ (-1). After 1000 cycles of charge and discharge, the capacity retention rate is up to 98.1%, which indicates that the composite has good cycling stability and is an ideal electrode material for supercapacitor.
【学位授予单位】：江苏大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TB33;TM53

【参考文献】