自支撑萘基聚酰亚胺复合纤维正极的分子设计、多孔构筑及其储锂性能研究

萘基聚酰亚胺以羰基官能团发生可逆的烯醇化氧化还原反应而储存能量，具有分子结构可设计、资源丰富、环境友好和易于加工等优点，被认为是理想的锂离子电池有机正极材料之一。针对目前萘基聚酰亚胺粉末易于团聚、导电性差、工作电压低和羰基官能团利用率低的关键问题，本项目拟利用分子结构设计、静电纺丝技术、原位热处理和微纳孔结构设计相结合的简单高效、一体化成型新策略构筑自支撑多孔萘基聚酰亚胺复合纤维膜，实现萘基聚酰亚胺均匀分散与良好的导电性和羰基官能团高效利用与工作电压的提升。系统研究萘基聚酰亚胺分子结构、静电纺丝参数和后处理工艺参数对自支撑多孔萘基聚酰亚胺复合纤维膜力学性能、导电性、多孔结构的影响，揭示自支撑多孔萘基聚酰亚胺复合纤维膜的萘基聚酰亚胺分子结构/力学性能/导电性-多孔结构-储锂性能之间的关系规律，阐明自支撑多孔萘基聚酰亚胺复合纤维膜的储锂机制及性能提升策略，为其在绿色锂离子电池中的应用奠定基础。

The naphthalene-based polyimide can store and convert energy by means of reversible enolization redox reaction of carbonyl groups, which has been considered as one kind of ideal organic cathode materials for lithium-ion batteries due to its advantages of structural designability, abundant resources, environmental benignity and easy processing. In view of the key problems of easy agglomeration, poor electrical conductivity, low operating voltage and utilization rate of carbonyl groups of the present naphthalene-based polyimide powders, this project intends to construct a free-standing porous naphthalene-based polyimide composite fiber membrane by using a simple and efficient new strategy combining molecular structure design, electrospinning technology, in-situ heat treatment process and micro/nanopore design. The as-prepared free-standing porous naphthalene-based polyimide composite fiber membrane can achieve homogeneous dispersion, good electrical conductivity, high efficient utilization of carbonyl groups and the improvement of operating voltage of naphthalene-based polyimide. In addition, the relationship between the content of each component, electrospinning parameters, post-processing parameters and molecular structure/mechanical properties/conductivity, porous structure and lithium storage performance of the as-prepared free-standing porous naphthalene-based polyimide composite fiber membrane will be thoroughly explored. Through the implementation of this project, it is expected to clarify the lithium storage mechanism and performance improvement strategies of the as-prepared free-standing porous naphthalene-based polyimide composite fiber membrane, which lays the foundation for its application in green lithium-ion batteries.