中空活性炭纤维/亚氧化钛混合电容器电极材料的可控制备及超电容性能研究

The application and popularization of supercapacitor are limited by its low energy density. The improvement of energy density of the electrode materials without sacrificing their power density and stability is the key issue to the development of high performance supercapacitor.The hybrid capacitor can show high energy density together with many merits, such as high power density and good stability, because it has characteristics of both electric double-layer capacitor and Faraday pseudocapacitor. Therefore, this project will carry out the controllable preparation and supercapacitive properties evaluation of the activated carbon hollow fibers (ACHFs) and titanium suboxide used as eletrode materials of hybrid capacitor. First of all, the ACHFs with high surface area, low resistance and proper pore structure will be prepared from biomass materials by template method under the adjustable carbonization and activation conditions. At the same time, nano-sized Magneli-phase titanium suboxide, with excellent electrochemical properties, will be produced under controlled conditions. Then the ACHFs/titanium suboxide hybrid capacitor will be assembled after the optimization design of each part of the capacitor. The effects of morphology and structure of materials on the electrochemical performances of the electrodes will be lucubrated in this project. This project will not only make a breakthrough in improving the energy density, power density and other performances of supercapacitor, but also provide new ideas for the development of supercapacitor electrode materials. In addition, the results of this project can be theoretical guidance and experimental basis for the development of high-performance supercapacitor.

能量密度低的缺陷限制了超级电容器的应用推广。如何在保证功率密度和稳定性的前提下，提高电极材料的能量密度是开发高性能超级电容器的关键问题。混合电容器综合了双电层电容和法拉第准电容两种储能机理，可在获得高能量密度的同时兼具功率密度高、稳定性好等优点。因此，本项目将开展中空活性炭纤维/亚氧化钛混合电容器电极材料的可控制备及其超电容储能特性的研究。首先以生物质类材料为碳源，利用模板法并控制炭化、活化条件制备具有高比表面积、低内阻、孔结构合理的中空活性炭纤维；控制合成条件制备电化学性能优异的Magneli相亚氧化钛纳米材料；优化组装亚氧化钛/中空活性炭纤维混合电容器；揭示材料形貌、结构等特性对电极电化学储能性能影响的规律和机理。通过本项目的研究，有望在提高超级电容器能量密度、功率密度等性能方面取得突破，为开发超级电容器电极材料提供新的思路和借鉴，并能为高性能超级电容器的发展提供理论指导和实验基础。

能量密度低的缺陷限制了超级电容器的市场应用推广。如何在保证功率密度和稳定性的前提下，提高电极材料的能量密度是开发高性能超级电容器的关键问题。针对该关键问题，本项目采用混合电容器体系，综合双电层电容和法拉第准电容两种储能机理的优势，在获得高能量密度的同时兼具功率密度高、稳定性好等优点。本课题以来源丰富、环境友好、价格低廉的天然生物质及废弃物材料为碳源，通过控制炭化、活化工艺条件制备出结构可控、比表面积大、导电性好的中空活性炭纤维及分级层次孔结构多孔炭材料，阐明了中空炭纤维材料及分级孔结构多孔炭材料的成孔及结构调控机理；揭示了所得炭材料的微观结构与电化学性能间的构效关系；通过调控和优化煅烧温度、时间和气氛等条件，制备出纯度达到99%的Magnéli相亚氧化钛纳米材料；探讨了亚氧化钛材料的制备条件对其组成及电化学性能的影响规律；以Magnéli相亚氧化钛纳米材料和中空活性炭纤维为正、负极组装成混合超级电容器，对体系进行正负极匹配与结构优化设计，提高了超级电容器的工作电压及能量密度，为进一步研究和开发新型高性能超级电容器提供理论依据和实验基础。