金属甲酸框架化合物基金属硫化物的制备与电化学性能研究

发布时间：2018-01-04 13:22

本文关键词：金属甲酸框架化合物基金属硫化物的制备与电化学性能研究　出处：《新疆大学》2017年硕士论文　论文类型：学位论文

【摘要】：超级电容器是一种环保、经济储能器件,具有能量密度高、性能稳定、充电时间短、环境影响小等特点,被广泛应用到军事、交通、航天等领域中。影响超级电容器性能的主要因素是电极材料的组成和结构,因此探究高性能的电极材料是当今研究热点。在众多的储能材料中,中空结构的金属硫化物具有环境友好、容量高和成本低廉等优点,是目前理想的储能材料之一。而金属有机框架化合物(MOFs)具有合成简单、形貌易于调控、原料易得价廉等特点,被认为是合成中空、多孔材料理想的前驱体。因此,本论文致力于以金属甲酸有机框架(MFFs)为前驱体,通过离子交换反应制备中空金属硫化物,并研究其电容特性,具体研究内容如下:一、以镍甲酸框架化合物Ni-MFF[CH_3NH_3][Ni(HCOO)3]为前驱体,通过离子交换反应,制备了分级结构中空立方体NiS,并探究了分级中空结构的形成机理。超级电容器性能测试结果表明:当电流密度为1 A g~(-1)时,分级结构中空NiS比电容可达874.5 F g~(-1),在电流密度为4 A g~(-1)下,经过3000圈循环后其比电容还能够保持初始值的90.2%。将NiS与煤基碳纤维组装成非对称电容器,在功率密度为387.5 W kg~(-1)时,能量密度可达34.9 Wh kg~(-1)。当用两个不对称扣式的电容器作为电源时,可以将1个蓝色的0.5 W LED灯泡点亮30 min,也可以把两个红的和一个黄的LED灯点亮10 min。二、室温下,通过调节反应物中甲酸、甲胺的比例,成功制备了两种不同形貌的Co-MFF前驱体[CH_3NH_3][Co(HCOO)3]。利用材料的形貌继承性,通过水热条件下的离子交换法将不同形貌的Co-MFF前驱体转化为空心结构Co3S4。两种不同形貌空心结构Co3S4的电容性能评价结果表明:空心立方块Cube-Co3S4在电流密度为1 A g~(-1)时,比电容可达546.5 F g~(-1),经过10000次恒流充放电后比电容还能够保持初始值96%;而空心四叶草形Microframes-Co3S4在电流密度为1 A g~(-1),比电容可达497.0 F g~(-1),经过10000次恒流充放电后比电容还能够保持初始值94%,结果表明合成的空心Co3S4具有良好的稳定性。三、室温下,通过改变反应溶剂、反应物甲酸及甲胺的滴加顺序,构建了三种不同形貌的CoNi-MFF前驱体[CH_3NH_3][NiCo2(HCOO)3];再经过离子交换反应制备出了空心立方体、空心椭球形、花球形的NiCo2S4。将合成的不同形貌的NiCo2S4进行电化学性能研究,花球形Microflower-Ni Co2S4表现出最高的比电容(在电流密度为1 A g~(-1)时,比电容可达1229 F g~(-1))和良好的稳定性(在电流密度为5 A g~(-1)下,循环5000圈能够保持初始值85%)。将花球形Microflower-NiCo2S4与碳纤维构建成非对称电容器,在功率密度为400 W kg~(-1)时,能量密度可达37.2Wh kg~(-1)。
[Abstract]:The super capacitor is a kind of environmental protection, economy of energy storage device with high power density, stable performance, short charging time, the characteristics of the environmental impact of small, has been widely applied to military, transportation, aerospace and other fields. The main factors affecting the performance of the super capacitor is the composition and structure of electrode materials, electrode materials and so on high performance is the hotspot. In many of the energy storage material, metal sulfide hollow structure has advantages of environmental friendly, high capacity and low cost, is an ideal material for energy storage. And one of the metal organic framework compound (MOFs) has a simple synthesis, easy to control the morphology, easy to get cheap raw materials other characteristics, is considered to be the precursor synthesis of hollow, porous materials ideal. Therefore, this paper is devoted to formic acid with metal organic framework (MFFs) as the precursor was prepared by the reaction of hollow metal sulfide by ion exchange and research The capacitance characteristics, the specific contents are as follows: a nickel formate framework compound Ni-MFF[CH_3NH_3][Ni (HCOO) 3] as precursor, through an ion exchange reaction, the hierarchical structure of hollow cubic NiS were prepared, and explore the formation mechanism of the graded hollow structure. The results show that the performance of the super capacitor when the current density is 1 A g~ (-1), the hierarchical structure of hollow NiS than the capacitance of 874.5 F g~ (-1), at a current density of 4 A g~ (-1), after 3000 cycles the specific capacitance can also maintain the initial value of the 90.2%. and NiS coal based carbon fiber assembly into asymmetric capacitor in power density 387.5 W kg~ (-1), the energy density can reach 34.9 Wh kg~ (-1). When the two asymmetric capacitor type button can be used as a power source, 1 Blue 0.5 W LED 30 min light bulb, can also put two red and one yellow LED lights 10 min. two, room temperature,. After adjusting the reactant acid, dimethylamine ratio of two different morphologies of Co-MFF precursor [CH_3NH_3][Co was prepared by using 3]. (HCOO) material morphology inheritance, the precursor of Co-MFF with different morphologies into hollow structure of Co3S4. capacitor performance evaluation of two different morphologies of hollow structure of Co3S4 the results show that the ion water heat under the condition of exchange method: hollow cube Cube-Co3S4 at a current density of 1 A g~ (-1), the specific capacitance can reach 546.5 F g~ (-1), after 10000 charge discharge specificcapacitance can also maintain the initial value of 96%; and the hollow clover shaped Microframes-Co3S4 at a current density of 1 A g~ (-1 the specific capacitance is 497 F), g~ (-1), after 10000 charge discharge specificcapacitance can also maintain the initial value of 94%. The results show that the hollow Co3S4 synthesis has good stability. Three, at room temperature, by changing the reaction solvent, reaction of formic acid And methylamine dropping sequence, construct three different morphology of CoNi-MFF precursor [CH_3NH_3][NiCo2 (HCOO) 3]; after the ion exchange reaction was prepared by hollow cube, hollow ellipsoid shaped head NiCo2S4. will synthesis different morphologies of NiCo2S4 on electrochemical properties of spherical Microflower-Ni flower Co2S4 exhibited the highest ratio the capacitor (at a current density of 1 A g~ (-1), the specific capacitance can reach 1229 F g~ (-1)) and stability (at a current density of 5 A g~ (-1), 5000 cycles can keep the initial value of 85%). The ball shaped Microflower-NiCo2S4 and carbon fiber construction into asymmetric capacitor in, the power density is 400 W kg~ (-1), the energy density of up to 37.2Wh kg~ (-1).

【学位授予单位】：新疆大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：O627;TM53

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