激光诱导同步合成氮掺杂石墨烯及图案化用于高效电能存储

Energy storage devices fabricated on flexible substrate possess significance for the development of portable and wearable electric equipments. However, the existing energy storage devices cannot meet the special requirement of flexible equipments due to their low energy density, large volume, bad flexibility, etc. The aim of program is to develop a laser processing technology for the synchronous synthesis, nitrogen doping and patterning of Graphene electrode on polyimide film. The Graphene electrode is then used in supercapacitor for highly efficient energy storage and release. The main research contents are listed below: (1) The design of polyimide films with different C-N bond configuration (pyridinic N, quaternary N, or pyrrolic N）in the backbone. The polyimide films will be exposed in laser irradiation to be transformed into Graphene by a serious of photophysical and photochemical processes. The mechanism of this transformation will be systematically studied in order to realize the accurate control of the amount and configuration of nitrogen doping in Graphene electrode. (2) In combination with theoretical calculation, the relation between the C-N configuration, the lattice defect and the electric structure, conductivity in nitrogen doped Graphene will be studied, to further understand the influence factors of specific capacitance. (3) Based on the above study, flexible energy storage devices with high energy density will be developed. The cycling stability of the devices under different bending degree will also be studied. The expected results of this program will provide theoretical and experimental basis for the application of laser processing technology on the fabrication of portable and flexible energy storage devices.

柔性基板上制备的能量存储器件对便携式可穿戴电子设备的发展具有重要意义。然而现有供能器件存在存储密度低、体积大、延展性差等不足，难以满足柔性设备能量供给的特殊需求。本项目拟利用激光加工技术，在聚酰亚胺薄膜上完成石墨烯电极同步的制备、氮掺杂和图案化，实现高效的电能存储和供给。主要研究内容如下：（1）设计主链含有不同C-N键合形式（吡啶氮、吡咯氮或季铵氮）的聚酰亚胺薄膜，研究其在激光作用下通过光物理或光化学过程转化为石墨烯的机制，以期实现对石墨烯氮掺杂浓度和掺杂形式的精确调控；（2）结合理论模拟，探索不同C-N键合形式及晶格缺陷与氮掺杂石墨烯的电子结构和电导率的关系，并进一步的研究其对石墨烯电极比电容的影响机制。（3）在以上工作基础上，优化设计出高储能密度的柔性超级电容器，并研究其在不同弯曲度下的循环稳定性。本项目的预期成果将为激光加工技术在轻质便捷柔性储能器件制造上的应用提供理论和实验基础。

石墨烯材料在构筑高能量密度、高功率密度超级电容器领域具有广泛的应用前景。本项目以激光加工技术为基础，以在柔性聚合物薄膜基底上实现原位规模化制备石墨烯电极阵列为目标牵引，结合多种物理、化学方法设计和制备了不同体系的石墨烯电极材料体系。重点探讨了激光诱导下含碳聚合物转变为石墨烯的光热作用机制，并以此为基础通过构筑增强光敏性的聚合物薄膜，实现更高的激光穿透深度，使得所制备的石墨烯厚度达到1个数量级的提升。同时研究了石墨烯的氮掺杂机理，实现超高浓度的石墨烯氮掺杂，表现出优异的电化学性能。进一步通过金属纳米粒子复合的方式，大幅提高石墨烯的电导率，并探索其器件应用。为了提升石墨烯制备效率，研究利用具有更大聚焦直径的高能电子束，实现了石墨烯制备效率的100倍提升。在上述工作基础上，成功将具有更高电容存储能力的多种赝电容材料与石墨烯进行复合，设计出高性能的超级电容器电极，并组装成具有实际应用价值的全固态柔性超级电容器。相关研究结果已经在Nanoscale、ACS Applied Nano Materials、Journal of Chemical Technology and Biotechnology、Materials and Design等国际SCI期刊上发表论文12篇，申请国家专利11项，已完成所有既定目标。