摘 要过渡金属化合物硫化钴有着理论超高比电容，但是经过多次恒电流充分放电后， 其体积发生膨胀，破碎甚至粉化。因此通过引进具有稳固平整结构石墨烯来弥补，且 石墨烯也具有优异的电化学性能，二者的复合材料是制备超级电容负极材料的理想材 料。本文采用水热法，以氧化石墨烯、氯化钴和硫脲为原料，以聚乙烯吡咯烷酮（PVP） 为分散剂，成功地制备了石墨烯基硫化钴复合材料。83176

采用拉曼光谱、X 射线衍射、场发射扫描电镜等一系列的表征技术对石墨烯基硫 化钴电极材料的结构和形貌进行了分析,通过循环伏安法、恒流充放电、交流阻抗等 手段研究了石墨烯基硫化钴电极材料的电化学性质。结果表明，硫化钴嵌入石墨烯后 其晶体结构没有发生变化，为六方晶体；在电流密度为 0。5 A g-1 下，石墨烯基硫化钴 复合材料比容量高达 426。8 F g-1，且循环 100 次后仍保持 91。7％的比电容；与纯的硫 化钴材料相比，石墨烯基硫化钴复合材料更小的溶液电阻和更小的界面电荷转移电阻， 同时有着更加良好的离子扩散传输电容性能。

毕业论文关键词：石墨烯，过渡金属硫化物，硫化钴，电容器

Abstract The transition metal compound cobalt sulfide has a theoretical ultrahigh capacitance, but after several fully constant current discharge its volume will expand, crush or powder。 Therefore, through adding graphene which has stable and flat structure and excellent electrochemical properties to cobalt sulfide, this compound becomes the ideal  material for the super capacitor anode。 In this paper, using Hydrothermal as method, hydrothermal of graphene oxide, cobalt chloride and thiourea as raw materials, polyvinylpyrrolidone (PVP) as a dispersing agent, cobalt sulfide graphene-based compound were prepared successfully。

Using a series of characterization techniques as raman spectroscopy, X-ray diffraction, field emission scanning electron microscope to analyze the structure and morphology of gaphene-based cobalt sulfide compound electrode material。 The electrochemical properties of gaphene-based cobalt sulfide electrode material was analyzed by cyclic voltammetry, constant current charge and discharge, AC impedance。 The results showed that the crystal structure of cobalt sulfide is still hexagonal crystal after embedding grapheme and has no change。 At a current density of 0。5 A g-1, the capacity of graphene-based cobalt sulfide composites can reach up to 426。8 F g-1, and the capacitance kept 91。7% after repeating 100 times。 Compared with the pure cobalt sulfide material, graphene-based composites cobalt sulfide has a smaller solution resistance and interfacial charge to transfer resistance, while it also has a better ion diffusion transfer capacitor performance。

Keywords: Graphene, transition metal sulfide, cobalt sulfide, capacitor

目 录

第一章 绪 论 1

1。1  引言 1

1。2  超级电容器的简介 1

1。2。1 超级电容器的特点 1

1。2。2 超级电容器的种类 2

1。2。3 超级电容器的电极材料 2

1。2。3 超级电容器的应用 2

1。3  石墨烯的简介 3

1。3。1 石墨烯的发现 3

1。3。2 石墨烯的性能 3

1。3。3 石墨烯的制备 4

1。3。4 石墨烯在电化学领域中的应用