基于细菌纤维素的共掺杂碳纳米纤维的宏量制备及其在超级电容器中的应用

Because of the wide application of supercapacitors in various fields, great efforts have been made to improve their electrochemical performances. It is well accepted that the properties of these devices are intimately dependent on their electrode materials. The introduction of heteroatoms into the carbon nanomaterials as the electrode materials is considered to be one promising method. Currently, certain achievements have been made in doping heteroatoms within the carbon materials, yet a lot of drawbacks still exist, for example, high cost of raw materials, harsh experimental conditions, time-consuming synthesis processes, and unfavorable device performances. With theoretical calculations, it has been found that the dual-doping of graphene can increase its quantum capacitance. However, few researchers so far have investigated the supercapacitive performances of dual-doped carbon materials. In this project, green, low-cost, efficient, and scalable methods are proposed to prepare dual-doped carbon nanowires from bacterial cellulose (BC), a cheap, renewable, and abundant biomass carbon source; moreover, the principle of the supercapacitors with dual-doped carbon nanofibers is systematically studied to reveal their synthesis mechanism. In summary, this project will not only provide novel idea for the design of dual-doped carbon nanomaterials, but also offer superior electrode materials for the high-performance supercapacitors.

超级电容器在诸多领域应用广泛，因此人们一直专注于提高其性能。其中，电极材料在影响超级电容器性质的因素中最为重要。在众多电极材料中，掺杂碳纳米材料被认为最有前景。目前，人们在制备掺杂氮、磷或硼的三维碳材料方面取得了一定的进展，但仍存在一些缺点，例如：原料成本高、合成条件苛刻、耗时费力、电容性质不好等。我们通过理论计算发现在碳材料中共掺杂一些原子能有效提高碳纳米材料的量子电容，而迄今很少有课题组深入研究共掺杂对碳材料超级电容器性能的影响。鉴于此，本项目基于便宜、环境友好且来源丰富的细菌纤维素作为碳源，设计环保、廉价、高效、可规模化的合成方法制备三维共掺杂原子碳纳米纤维，并系统研究共掺杂对碳纳米材料电容性能影响的机理。同时，揭示共掺杂原子碳纳米纤维的形成机理。本项目的实施，不仅为共掺杂原子碳纳米纤维的合成提供新的设计思想，而且为构筑高性能超级电容器提供了新型、优良的电极材料。

电化学能源存储器件（超级电容器、锂离子电池、锂硫电池等）的电极研发过程中急需高性价比的材料。本项目基于细菌纤维素、花粉等廉价环保的生物质作为碳源，结合掺杂杂原子可以改变碳材料的电子结构并增强其导电性而复合一定的金属氧化物可有效提高储能大小，开发出具有较高功率密度的超级电容器、较大储存锂离子和较长循环寿命的锂离子电池负极材料、长循环寿命的锂硫电池隔膜。其中，主要发现和成果如下：（1）提出了几种掺杂原子碳材料的设计原理和制备方法；（2）发展了绿色环保、低成本、高性能能源存储器件电极材料的方法，为新型能源材料的制备提供了新手段；（3）实现了高性能能源存储器件电极材料的宏量制备，为进一步规模化合成高性价比的能源材料提供了理论和技术指导。在上述研究工作中，我们获得了多项具有一定创新性和系统性的成果，部分研究工作已经在Advanced Energy Materials、Nano Research、Chemical Engineering Journal、Inorganic Chemistry Frontiers、Account of Chemical Research等国际期刊上发表，其中2篇成果入选ESI高被引用论文，1篇选为封面论文。