TiO2纳米管阵列的多重功能化及其全固态超电容特性研究

As a new clean, high efficient energy storage device, supercapacitor has broad prospects for development in the fields of green energy and ecological environment. This project intends to develop a target-determined multiple hybrid anodizing process for the controllable fabrication of hierarchical structured TiO2 nanotube arrays. Through the fine coordination of multiple hybrid anodizing process parameters, TiO2 nanotube arrays with different hierarchical structure characteristics and transition layer thickness could be prepared. Then MnO2 nanoparticles with high specific capacitance would be deposited by electrochemical deposition process, forming a hierarchical structure of MnO2/TiO2 nanotube arrays. In order to further exert the supercapacitive characteristics of carbon materials, the as-built MnO2/TiO2 hierarchical composites afterward would be annealled among acetylene atmosphere. The flexible all-solid-state supercapacitor device would then be assembled. During the assembling process, polypyrrole (PPy) would be incorporated to wrap the hierarchical structured C-MnO2/TiO2 film, and HClO4-polyvinyl alcohol (PVA) gel would be adopted as the solid electrolyte layer. Cyclic voltammetry, constant current charge/discharge characteristics and attenuation characteristics of the specific capacitance of C-MnO2/TiO2 materials would be systematically investigated. The research results of this project will expand the application range of TiO2 nanotube arrays. And we will develop a new kind of supercapacitor electrode material based on the ordered nanoarray materials for flexible all-solid-state supercapacitor devices. The research progress would provide theoretical basis and materials support for high efficient supercapacitors.

超级电容器作为一种清洁、高效的新型储能器件，在绿色能源和生态环境领域有着广阔的发展前景。本项目拟采用目标调控的多次杂化阳极氧化工艺，实现分级结构TiO2纳米管阵列的可控构筑,通过精细协调多次杂化阳极氧化工艺参数，制备不同尺度分级结构特征及过渡层厚度的TiO2纳米管阵列；进而采用电化学沉积工艺在所构筑分级结构TiO2纳米管阵列内沉积高比电容量的MnO2纳米颗粒，并将MnO2/TiO2进行表面碳化，进一步利用碳材料自身的超级电容特征；引入PPy附着并包裹分级结构的C-MnO2/TiO2膜层，以酸化PVA凝胶为固态电解质层，组装柔性全固态超级电容器原理型器件，研究C-MnO2/TiO2材料的循环伏安特性、恒电流充放电特性及比电容量衰减特性；拓展阳极氧化TiO2纳米管阵列的应用范围，发展一种基于有序纳米阵列材料的柔性全固态超级电容器件，为超级电容器电极材料的发展提供理论依据和材料支撑。

纳米尺度的赝电容材料对于提高超级电容器的能量密度和功率密度具有重要意义。本项目在常规阳极氧化技术制备TiO2纳米管阵列的基础上，进一步采用正交试验设计及改进型的阳极氧化工艺制备了表面超平整且纳米管管径一致的TiO2纳米管阵列薄膜。通过采用氩气保护的退火工艺，实现了在TiO2纳米管内部引入氧空位，增加载流子密度，极大提高了TiO2纳米管阵列的电导性，并且保持了TiO2纳米管阵列的有序形貌特征，同时在纳米管阵列表面包覆一层均匀的碳层。再借助碳层的还原性，进一步采用水热沉积法合成三层同轴MnO2/Carbon@TiO2纳米管阵列复合材料，该MnO2/Carbon@TiO2复合纳米阵列薄膜表现出优越的电容特性，拥有更高的比电容量和更长的循环寿命。继而将MnO2/TiO2纳米管电极作为正负极材料组装对称型全固态超级电容器。结果表明MnO2/TiO2纳米管复合阵列对称全固态超级电容器具有较高的能量密度，在电流密度5A/g下首次充放电比电容为39.9F/g，并且5000圈循环充放电后比电容保持率为91.5%。