三维石墨烯复合物和二维高分子的合成和电化学能源应用探索

Three-dimensional Graphene-based Composites and Two-dimensional Polymers: Synthesis and Application in Energy Storage and Conversion

石墨烯是具有单原子厚度的二维碳原子晶体,也是一种独特的天然二维高分子.柔性石墨烯片层可以通过三维组装形成多孔的块体材料,从而将单个微观石墨烯的特性有效的发挥到宏观材料层面,推进石墨烯的实际应用.与此同时,随着人类社会对绿色可持续性能源的不断需求,基于石墨烯开发高效的电化学能源存储与转换材料成为当前研究的重要课题.受石墨烯这一天然二维高分子结构的启发,科学家们希望从原子或分子层面进一步理性设计合成新型二维高分子,获得新的骨架联接并具有优异可加工性能的新型二维材料并探索其在能源等领域的应用,这一研究领域充满巨大挑战.本专论将系统介绍我们设计合成了一系列新型电化学活性材料并与三维石墨烯有效复合制备成三维石墨烯复合物,以及灵巧合成了几种新型骨架联接的二维高分子材料,并重点实现这两个相辅相成方向在电化学能源存储和转化方面的应用探索,为解决电化学能源需求问题提供崭新的突破口.

A carbon sheet with single-atom thickness, graphene is unique for its nature in two-dimensional polymers (2DP). Recently, three-dimensional (3D) graphene architecture assembled from flexible 2D graphene via non-covalent interaction has attracted great attention, for the collective interaction between graphene sheets enables various functional advances while having the intrinsic properties of individual sheet well preserved. Typical macrostructures of 3D graphene involve hierarchical porosity, large specific surface area, superior mechanical strength, and excellent electrical conductivity, which endow this emerging material with great potential in catalytic, environmental, biomedical, and to the upmost importance, energy-related applications. Evergrowing concerns caused by fossil fuels about sustainability and environmental issues have urged extensive research on high-performance materials for electrochemical energy storage and conversion. Taking advantage of the controlled synthesis of novel electrochemically active nanomaterials and their efficient integration with 3D graphene framework, our group is innovatively developed several versatile strategies and successfully fabricated a series of 3D graphene composites. Carrying elaborate microstructures and synergistic effect, as-obtained materials demonstrate outstanding electrochemical performance when employed in flexible electrodes and devices such as supercapacitors, lithium/sodium-ion batteries, lithium-sulfur batteries, and electrocatalysts. Our studies have been decently recognized as effective solutions to address the impending energy problems. Meanwhile, the natural 2DP attribute of graphene has aroused great enthusiasm for rational organic synthesis of new 2DPs at the atomic or molecular level. The controllable synthesis of 2DPs with tailored molecular structure and excellent processability can promote immensely the progress of polymer synthetic chemistry. Further, it exhibits vast strength in the development of novel polymeric materials that hold desirable properties and functions rare in conventional onedimensional polymers. Since it is challenging but meaningful in the energy arene to design and synthesize 2DPs that integrate simultaneously 2D conjugated plane, in-plane uniform micropores, and electrochemical active groups. This feature article summarizes the synthesis of 3D graphene-based composites and 2DPs progressed in our group, followed by their applications in energy storage and conversion. The contribution ends with brief discussions and outlook about the future challenges and opportunities of graphene materials and relevant research field.