镍的双金属氧化物的合成及其电化学储能性能的研究

发布时间：2019-03-20 16:13

【摘要】：本论文主要使用简单、廉价、环保的方法合成具有优异电化学储能性能的电极材料,然后通过XRD、XPS、SEM、TEM等仪器对材料的形貌和结构进行详细的分析,最后通过循环伏安、恒电流充放电、交流阻抗等电化学测试方法对单电极材料及组装的非对称超级电容器进行电化学储能性能分析,具体研究内容包括以下几个方面:1.通过一步水热法,以异丙醇为溶剂,在三维的网状泡沫镍上生长多孔的Co1.29Ni1.71O4纳米片,通过SEM可以看到不规则的Co1.29Ni1.71O4纳米片完全覆盖在泡沫镍基底上,纳米片之间有很多不规则的孔。直接以NF@Co1.29Ni1.71O4作为工作电极,在三电极体系中通过恒电流充放电对单电极材料进行电化学性能测试,在5 m A cm-2的电流密度下,其能持续放电近700 s,面积电容高达6.75 F cm-2,在50 m A cm-2的电流密度下,其面积电容保留值为74.4%,这些性能明显优于其它镍钴氧化物。2.使用简单、低耗能、绿色环保的一步水热法在泡沫镍上生长三维的石墨烯,成功地合成了三维的石墨烯泡沫(NF@r GO),然后通过水热和高温退火将超薄的Ni Mo O4纳米片原位生长在三维的石墨烯泡沫上(NF@r GO@Ni Mo O4),通过SEM可以清晰看到Ni Mo O4为蜂窝状的纳米片状结构和石墨烯的褶皱,直接以NF@r GO@Ni Mo O4为工作电极,在三电极体系中使用不同的电化学方法进行电化学性能测试,表现出优异的倍率性能(56%的电容保留,1到20 m A cm-2)和循环稳定性(93.1%的电容保留,1000次循环)。3.使用简单的方法以泡沫镍为基底合成了Co2Ni O4、Ni Mn2O4及其复合物Co2Ni O4@Ni Mn2O4,分别进行SEM形貌分析,发现Co2Ni O4为分层的纳米片状结构,Ni Mn2O4为类似花瓣状的薄片结构,复合物Co2Ni O4@Ni Mn2O4成功保留了Co2Ni O4纳米片状结构和Ni Mn2O4的花瓣状的薄片结构,花瓣状的Ni Mn2O4薄片覆盖在Co2Ni O4纳米片上,在TEM中可以清晰看见这两种化合物的分界。直接以NF@Co2Ni O4@Ni Mn2O4为工作电极进行电化学性能测试,在30 m A cm-2的电流密度下,其面积电容高达13.35 F cm-2,以NF@Co2Ni O4@Ni Mn2O4作为正极,石墨烯涂在泡沫镍上作为负极组装成非对称超级电容器(NF@Co2Ni O4@Ni Mn2O4//r GO),在3 M KOH碱性电解液中,其表现出宽的电势窗(0-1.8 V),功率密度为292.2 m W cm-2时,能量密度为1.38 m Wh cm-2,能量密度为3.01 m Wh cm-2时,功率密度为58.23 m W cm-2。
[Abstract]:In this thesis, the electrode materials with excellent electrochemical energy storage properties were synthesized by simple, cheap and environmentally friendly methods. Then the morphology and structure of the materials were analyzed in detail by means of XRD,XPS,SEM,TEM and other instruments, and finally, the cyclic voltammetry (CV) was used to analyze the morphology and structure of the materials. Electrochemical energy storage properties of single electrode materials and assembled asymmetric supercapacitors were analyzed by constant current charge / discharge, AC impedance and other electrochemical measurements. The main contents of this study are as follows: 1. Porous Co1.29Ni1.71O4 nanoparticles were grown on three-dimensional reticulated nickel foams by one-step hydrothermal method using isopropanol as solvent. Through SEM, we can see that irregular Co1.29Ni1.71O4 nanoparticles are completely covered on the foamed nickel substrate. There are many irregular holes between the nanoparticles. Using NF@Co1.29Ni1.71O4 as the working electrode, the electrochemical performance of the single electrode material was measured by constant current charge and discharge in the three electrode system. At the current density of 5 Ma / cm-2, the single electrode material could be continuously discharged for nearly 700s. The area capacitance of 6.75 F cm-2, is 74.4% at the current density of 50 Ma / cm-2, which is much better than that of other nickel cobalt oxides. Three-dimensional graphene foam (NF@r GO),) was successfully synthesized by one-step hydrothermal growth of three-dimensional graphene on nickel foam with simple, low energy consumption and green environment protection. Then the ultra-thin Ni Mo O 4 nanoparticles were grown on three dimensional graphene foam (NF@r GO@Ni Mo O 4) by hydrothermal and high temperature annealing. Through SEM, we can clearly see that Ni Mo O 4 is honeycomb-like nano-flake structure and graphene fold. Using NF@r GO@Ni Mo O 4 as the working electrode, different electrochemical methods were used to test the electrochemical performance in the three electrode system. The electrochemical performance was excellent (56% capacitive retention). 1 to 20 Ma cm-2) and cycle stability (93.1% capacitive retention, 1000 cycles). 3. Co2Ni O _ 4 was synthesized by a simple method based on nickel foam. The morphology of Ni-Mn2O4 and its complex Co2Ni O4@Ni Mn2O4, were analyzed by SEM. It was found that Co2Ni-O _ 4 was a layered lamellar structure and Ni Mn2O4 was a petal-like lamellar structure. The composite Co2Ni O4@Ni Mn2O4 successfully retained the Co2Ni / O _ 4 nanoflake structure and the Ni Mn2O4 petal-like lamellae structure, and the petal-like Ni Mn2O4 lamellae was covered on the Co2Ni / O _ 4 nano-sheet. The delimitation of the two compounds could be clearly seen in TEM. At the current density of 30 Ma / cm-2, the area capacitance is up to 13.35 F / cm-2, with NF@Co2Ni O4@Ni Mn2O4 as the positive electrode. The electrochemical performance of NF@Co2Ni O4@Ni Mn2O4 is measured directly by using NF@Co2Ni O4@Ni Mn2O4 as the working electrode. Graphene coated on nickel foams was assembled as a negative electrode to form an asymmetric supercapacitor (NF@Co2Ni O4@Ni Mn2O4//r GO),) with a wide potential window (0 / 1.8 V),) in a 3 M KOH alkaline electrolyte. The power density is 292.2 MW cm- 2, the energy density is 1.38 m Wh cm-2, energy density is 3.01 m Wh cm- 2, the power density is 58.23 MW cm-2..
【学位授予单位】：暨南大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TB383.1;O646

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