Graphene-based, two dimensional porous ionic polymer networks and carbon nanosheets for supercapacitors

石墨烯因其高的最大比表面积、上级导电性和二维（2D）电荷传输能力而被认为是超级电容器电极材料的最有前途的候选者之一。然而，石墨烯纳米片显示出高的再聚集和堆叠在一起的趋势。在本项目中，我们提出将石墨烯与多孔离子聚合物功能化，制备石墨烯基多孔离子聚合物骨架，结合石墨烯和多孔离子聚合物的优点，提高超级电容器的性能。石墨烯的2D结构允许在两侧上生长均匀的多孔离子聚合物壳。由此，可以有效地抑制石墨烯片的聚集和重新堆叠。石墨烯基多孔离子聚合物骨架的导电性可以通过利用石墨烯的高导电性来提高。同时，多孔聚合物壳将赋予石墨烯基多孔聚合物框架赝电容。多孔聚合物的孔结构和孔参数可以定制，由于在选择和设计的积木广泛的灵活性。本论文主要研究石墨烯基多孔离子聚合物骨架的储能机理以及石墨烯与多孔离子聚合物之间的协同效应。此外，离子型聚合物还可以作为前驱体用于碳材料的制备。与常规聚合物前体相比，具有固有离子性质和离子对中的强库仑相互作用的带电聚合物可导致前体的高热稳定性，这减少了分解过程开始之前的质量损失。因此，石墨烯基离子聚合物可以用作制备用于超级电容器的多孔碳纳米片的前体。各种杂原子可以通过改变结构体被引入到碳纳米片中。本论文将系统研究不同杂原子碳纳米片的超级电容性能，合成工作在伍珀塔尔，器件工作在南昌。

Graphene is considered as one of the most promising candidates for the electrode materials of supercapacitors due to its high maximum specific surface area, superior electrical conductivity, and two-dimensional (2D) charge transport ability. However, graphene nanosheets show a high tendency for reaggregation and stack together. This inevitable reaggregation and stacking significantly decreases the electrochemically active surface area, thus resulting in a deteriorated supercapacitor performance.In this project, we propose to functionalize graphene with porous ionic polymers to generate graphene-based porous ionic polymer frameworks, which integrate the advantages of both graphene and porous ionic polymers to improve the performances of supercapacitors. 2D structure of graphene allows for the growth of uniform porous ionic polymer shells onto both sides. Thereby, the aggregation and restacking of the graphene sheets can be effectively suppressed. The conductivity of the graphene-based porous ionic polymer frameworks can be increased by taking the advantage of the high electrical conductivity of graphene. Meanwhile, the porous polymer shells will endow graphene-based porous polymer frameworks with pseudocapacitance. The porous structure and pore parameters of porous polymers can be tailored owing to the wide-ranging flexibility in the choice and design of building blocks. The energy storage mechanism of graphene-based porous ionic polymer frameworks and the synergistic effect between graphene and porous ionic polymers will be investigated. Besides, ionic polymers could be used as precursors for the preparation of carbonaceous materials. Compared with conventional polymeric precursors, charged polymers with intrinsic ionic nature and strong Coulombic interactions in ionic pairs may lead to high thermal stability of the precursor, which reduces mass loss before the decomposition process begins. Thereby, graphene-based ionic polymers could be used as precursors to prepare porous carbon nanosheets for use in supercapacitors. Various heteroatoms can be incorporated into the carbon nanosheets by changing the tectons. The supercapcitor performance of the carbon nanosheets with different heteroatoms will be systematically investigated.The synthetic work will be done in Wuppertal, the device work in Nanchang.