柔性可拉伸聚吡咯/聚丙烯酸复合水凝胶电极3D多孔结构的调控及储能机理研究

It is difficult for conductive polymers to obtain satisfied flexibility and cycle stability due to its rigid backbone. Research of flexible conductive polymer composites with stable micro/nanostructure has stimulated a great interest. In this project, chemical crosslinked polyacrylic acid is used as the backbone of the conductive polypyrrole composite hydrogel. One step in situ polymerization method is used to prepare stretchable polypyrrole/polyacrylic acid composite hydrogel with semi interpenetrating double crosslinked structure. Anthraquinone grafting graphene is further introduced to control the 3D hierarchical porous structure as well as increase the electrochemical performances. The effect of competitive mechanism between radical and oxidant polymerization on the regulation of 3D porous structure will be studied. Other effects, such as crosslinking density, grafting structure of graphene and interface microstructure, on the change of 3D porous structure and electrochemical performances of the electrode before and after stretching will be investigated. Based on these results, the relationship between 3D porous structure and supercapacitive performances of the composite hydrogel as well as the energy storage mechanism inside the hydrogel pores will be constructed. The research of this project will provide both experimental and theoretical basis for the design and construction of novel flexible supercapacitor electrode materials.

导电聚合物的刚性主链使其作为电极材料很难获得满意的柔韧性与循环稳定性，具有稳定微/纳米结构的柔性导电聚合物复合材料的研究正日益受到关注。本项目拟采用化学交联的聚丙烯酸作为导电聚吡咯复合水凝胶的支撑骨架，利用原位聚合“一步法”制备3D半互穿双交联结构的可拉伸聚吡咯/聚丙烯酸复合水凝胶；并引入蒽醌接枝石墨烯，进一步调控复合水凝胶电极的3D分级多孔结构及电化学性能。研究自由基与氧化聚合竞争机制对3D多孔结构的调控规律，探讨交联密度、石墨烯接枝结构、界面微结构等对电极拉伸前后3D多孔结构及电化学性能的影响规律。建立3D多孔结构内部储能机理，阐明复合水凝胶3D多孔结构与超电容特性的构效关系，为设计和构筑新型柔性超级电容器电极材料提供实验和理论依据。

本项目采用自由基聚合与氧化聚合技术相结合制备得到了柔性、可拉伸聚吡咯/聚丙烯酸复合水凝胶，然后以这种3D网络结构为基础，引入电活性石墨烯、掺杂剂，利用原位聚合一步法制备得到了多孔结构可控、高拉伸（伸长率>300%)、高电导率的导电聚吡咯复合电极材料。电化学测试结果表明，复合电极材料展现出高的比电容、宽的电位窗口及良好的循环稳定性。其组装为超级电容器显示出高的能量密度、功率密度及循环稳定性。在上述基础上，深入研究了自由基与氧化聚合竞争机制、氧化剂、引发剂及掺杂剂选择、制备条件对电极材料的3D多孔结构以及电化学性能等的影响，阐明3D多孔结构构筑与超电容特性的构效关系，为设计和构筑新型柔性超级电容器电极材料提供了实验和理论依据。