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

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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.