石墨烯-多孔炭三维网络结构的构筑及其结构与电化学性能之间的关系

Advanced design ideas about the construction of “Sintered falling cards”-graphene-porous carbon three dimensional network architecture are introduced firstly to solve common problem that graphene sheets have a high tendency to restack themselves during graphene preparation and subsequent electrode production procedures, leaving behind intergraphene pore sizes that are not sufficient for accessibility to the electrolyte and the formation of EDLC charges. After modified by the block copolymer, the graphene ternary compound system come into being by the polymerization of the carbon precursor monomers along the block copolymer and succedent carbonization. The project mainly research on the forming, controlling and stabilizing of graphene-based composite’s micro-phase structure and the rules of structural evolution during pyrolysis and carbonization process. The synergistic effect between graphene, block copolymer and carbon precursor polymer in composite and their pyrolysis and carbonization behavior, the relationship between bequeathed configuration and micro-phase structure of composite and the relationship between network structure and electrochemistry capacitance characteristics will be thoroughly discussed. The structure evolution rules of composite during pyrolysis and carbonization process and the formation mechanism of channels structure would be clarified. Approaches of controlling micro-phase structure of composite and adjusting the structure and properties of graphene-porous carbon composite would be established. This research has great academic significance and practical value on developing the theory and technology of polymer blending carbonization and enriching the theory and technology of blending modification.

针对石墨烯处理过程中容易堆叠而导致比表面积利用率低的共性问题，提出以石墨烯为主体，多孔炭“桥接”的 “Sintered falling cards”的材料设计思想，保证石墨烯网络结构的形成和稳定。采用嵌段聚合物对氧化石墨烯进行改性，同时炭前驱体单体以嵌段聚合物为导向聚合，形成以嵌段共聚合物/炭前驱体聚合物为“链桥”的石墨烯三元复合体系，进一步炭化获得石墨烯-多孔炭三维网络结构。主要研究石墨烯三元复合体系微相结构的形成、控制、稳定及其热解炭化过程中的结构演变规律。探讨石墨烯、嵌段共聚合物和炭前驱体聚合物的协同作用与热解炭化行为；复合体系的遗态结构与微相结构的关系；石墨烯-多孔炭复合材料的电化学电容特性与网络结构的关系。阐明复合体系在炭化过程中的结构演变规律和通道结构形成机制，确立调控复合体系微相结构和石墨烯-炭复合材料结构与性能的途径。研究对于丰富碳基复合材料理论和技术具有重要学术意义。

针对石墨烯处理过程中容易堆叠而导致比表面积利用率低的共性问题，本项目提出了以石墨烯为主体，多孔炭“桥接”的“Sintered falling cards”的材料设计思想，建立稳定的石墨烯网络结构。采用糖类，酚醛树脂单体，双氨基化合物等对氧化石墨烯进行接枝共聚改性，炭化后形成了以石墨烯为支架，多孔炭为桥链的石墨烯-多孔炭三维网络结构。研究了石墨烯三元复合体系微相结构的形成、控制、稳定及其热解炭化过程中的结构演变规律。探讨了石墨烯和炭前驱体聚合物的协同作用与热解炭化行为以及石墨烯-多孔炭复合材料的电化学电容特性与网络结构的关系。主要包括以下几方面工作：1）发现糖类分子会在水热条件下在氧化石墨烯表面发生缩聚并炭化，改变了石墨烯表面的应力分布，使得原本较为平整的石墨烯卷曲成花型形貌。这样有利于抑制石墨烯片层的堆叠，使石墨烯具有较丰富的孔隙结构。2）发现了酚醛树脂单体会优先在石墨烯表面聚合，并会和石墨烯形成三明治形式的夹心结构，由于石墨烯的存在，这种三明治结构的复合材料在非活化条件下炭化过程中产生了丰富的微孔结构，比表面积最高达到1178 m2/g。3）利用含有双氨基的吡啶单体与氧化石墨烯发生接枝反应，利用双氨基吡啶分子作为桥链构筑石墨烯三维结构。改善了石墨烯材料与电解液的浸入性，同时证实了吡啶氮的电化学活性。该方法仅用室温进行，得到的石墨烯电极材料的比容量达到359.4 F/g。