纳米阵列复合电极材料的制备及其电化学性能研究

发布时间：2018-05-12 06:50

本文选题：超级电容器 + 纳米阵列　；参考：《浙江工业大学》2015年硕士论文

【摘要】：超级电容器作为一种新兴的储能元器件,以其功率密度大、循环寿命长、充放电速度快等优点,受到越来越多的关注。而决定超级电容器电化学性能的主要因素是电极材料,过渡金属氧化物电极材料由于可以发生可逆的电化学反应而具有明显优于碳材料的电容性能。相关研究表明,高度有序的纳米阵列电极结构具有较大的比表面积,优良的导电性和高速的离子/电子传输通道等特点。同时,纳米阵列电极用作超级电容器电极材料时,并不需要使用粘接剂和导电添加剂,可以有效提高活性材料的利用率。当进行多种材料的复合设计时,通过不同材料之间的协同效应,可使纳米复合材料具有优于任一单相材料的性能。本文旨在合成不同一维纳米阵列复合材料,以提高超级电容器的电化学性能。主要研究内容由以下两部分组成:1、通过电化学阳极氧化法首先在钛片上制备了TiO_2纳米管阵列,并以此为基底,采用水热法负载了MnO_2纳米颗粒。在制备过程中,将TiO_2纳米管在氢气中进行煅烧前处理后,制得的H-TiO_2/MnO_2复合材料具有更好的导电性。为了进一步增加材料的导电性,利用水热法将在氢气煅烧处理后的TiO_2纳米管进行碳包覆,获得的H-TiO_2/C材料,不仅具有更高的电导率,同时也能很好的利用TiO_2纳米管的比表面积增大MnO_2的负载量,提高MnO_2的利用率。H-TiO_2/C/MnO_2电极材料在0.5 A g-1的电流密度下具有高达66.2 mF cm-2(299.8 F g-1)的比电容,并具有较好的循环性能,是性能优异电极材料。2、通过水热法制备了NiCo_2O_4纳米线阵列,后又以此为基底分别采用水热法、化学浴沉积法制备了NiCo_2O_4@MnO_2,NiCo_2O_4@NiO纳米线阵列复合电极。NiCo_2O_4纳米线阵列基底,比表面积大、导电性好,表现出优异的电化学性能。NiCo_2O_4@MnO_2复合材料,由于壳层负载的MnO_2导电性差,结构致密,限制了内核NiCo_2O_4赝电容的发挥,导致NiCo_2O_4@MnO_2复合材料的比电容较NiCo_2O_4有所下降。NiCo_2O_4@NiO复合物具有明显优于NiCo_2O_4、NiCo_2O_4@Mn O2的电容性能,在1 A g-1的电流密度下比电容达到了1453.26 F g-1。但是,由于NiCo_2O_4@NiO复合物在循环过程中结构发生了变化,导致循环稳定性较差。选用导电性良好,结构疏松的壳层材料有利于增大复合物的比电容。同时,制备的复合物结构要足够稳定,以提高循环稳定性。
[Abstract]:As a new kind of energy storage components, supercapacitors have attracted more and more attention due to their high power density, long cycle life, high charge and discharge speed and so on. The main factor that determines the electrochemical performance of supercapacitors is the electrode material. The transition metal oxide electrode material is superior to the carbon material because of the reversible electrochemical reaction. Related studies show that the highly ordered nanoarray electrode structure has a large specific surface area, excellent conductivity and high speed ion / electron transport channel and so on. At the same time, nano-array electrodes can effectively improve the utilization of active materials when they are used as electrode materials for supercapacitors without the need of adhesive and conductive additives. When the composite design of many kinds of materials is carried out, the performance of nanocomposites is superior to that of any single phase material through the synergistic effect among different materials. In order to improve the electrochemical performance of supercapacitors, different one-dimensional nanoarray composites were synthesized. TiO_2 nanotube arrays were prepared on titanium wafer by electrochemical anodic oxidation method. The MnO_2 nanoparticles were loaded on the substrate by hydrothermal method. In the process of preparation, the TiO_2 nanotubes were calcined in hydrogen, and the H-TiO_2/MnO_2 composites had better electrical conductivity. In order to further increase the conductivity of the materials, the TiO_2 nanotubes calcined in hydrogen were coated with carbon by hydrothermal method. The obtained H-TiO_2/C materials not only have higher conductivity, At the same time, the specific surface area of TiO_2 nanotubes can also be used to increase the loading capacity of MnO_2, to increase the utilization ratio of MnO_2. H-TiO2 / C / MnO2 electrode material has a specific capacitance of up to 66.2 MF cm-2(299.8 F g-1 at the current density of 0.5 A g ~ (-1), and has good cycling performance. The NiCo_2O_4 nanowire array was prepared by hydrothermal method, and then it was used as a substrate, respectively, by hydrothermal method and chemical bath deposition method. NiCo2O4MnO2NiCo2O4NiCO2O4NiO nanowire array composite electrode, NiCo2O4Ni2O4NiO nanowire array composite electrode, NiCo2O4NiO wire array composite electrode. NiCo2O4NiOSIV nanowire array substrate, with large specific surface area, was prepared by chemical bath deposition method. Good electrical conductivity, showing excellent electrochemical performance. NiCo2O-4MnO-2 composite. Due to the poor conductivity and dense structure of MnO_2 loaded in the shell, the use of the pseudo-capacitance of the core NiCo_2O_4 is limited. The specific capacitance of NiCo_2O_4@MnO_2 composite is lower than that of NiCo_2O_4. The specific capacitance of the NiCo_2O_4@MnO_2 composite is obviously superior to that of NiCo2O4C / NiCo2O4MNO _ 2. The specific capacitance of the NiCo_2O_4@MnO_2 composite has reached 1453.26 F g ~ (-1) at the current density of 1A g ~ (-1). However, the structure of NiCo_2O_4@NiO complex changed during the cycle, which resulted in poor cyclic stability. It is advantageous to increase the specific capacitance of the composite by selecting the shell material with good conductivity and loose structure. At the same time, the structure of the prepared composite should be stable enough to improve the cycle stability.
【学位授予单位】：浙江工业大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：O646.54;TB383.1

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