仿葱卷结构石墨烯基微米棒的宏量制备及其在锂电池中的应用研究

Graphene-based one-dimensional (1D) macroscopic assemblies have attracted plenty of attention owing to its unique and excellent physicochemical properties. To date, many efforts have been devoted to improve their basic performance by doping or optimization and explore their potentially valuable applications, and has achieved a great progress. But the research of graphene-based 1D macroscopic assemblies related to the reasonable structural design, potential performance exploration and unique application development are still far from enough, while the study of the graphene-based 1D macroscopic assemblies is still restricted to some simple electronics such as lightweight conductors, supercapacitors, actuators et al. Therefore, it is of great research value and practical significance to further develop new graphene-based 1D macroscopic architectures, optimize the corresponding properties and explore suitable applications. In this context, this project aims to develop new graphene-based 1D nano-assembly structural materials, and further explore their application in the field of lithium batteries based on their unique structure and component characteristics. Specifically, to develop several new simple and versatile assembly methods of graphene-based microrods (GBMRs) and obtain a series of scallion-like GBMRs; with such GBMRs as unique 1D carbon scaffolds, to realize the dimensionally-confined adsorption, storage and utilization of lithium metal, the universally high load of the positive active materials, and prepare the corresponding high-energy and high-rate lithium batteries. This project strives to open a new avenue to explore and broaden applications of graphene as additives in lithium batteries from the perspective of microstructure design.

石墨烯基一维宏观纳米组装体由于其独特的物理化学性质，引起了人们的广泛关注与高度重视。然而，当前石墨烯基一维纳米组装体的研究仍然停留在掺杂赋予其新性质，优化提升其个别性能上，虽然其部分性能已很突出，但是其应用还主要停留在轻质导线、超级电容器、驱动器等简单器件领域，其结构设计、性能发挥和应用开发还远远不够，因此进一步拓展石墨烯基一维宏观结构，优化其性质，探索其应用具有重要的研究价值与意义。基于此，本项目旨在开发新型石墨烯基一维纳米组装结构，并立足其独特的结构与组分特征，进一步拓展其在锂电池领域应用。具体为发展几种简单、通用的石墨烯基微米棒高效制备工艺；以石墨烯基微米棒为一维碳框架，实现锂金属在微米棒3D空间内的定向吸附、存储与利用，正极活性物质高含量、通用性负载，实现其在高能量密度、高倍率锂电池领域中的应用，力争从微观结构设计角度，为石墨烯作为添加剂在锂电领域的应用提供了一个新的思路。

石墨烯基一维宏观纳米组装体由于其独特的物理化学性质，引起了人们的广泛关注与高度重视。然而，当前石墨烯基一维纳米组装体的研究仍然停留在掺杂赋予其新性质，优化提升其个别性能上，虽然其部分性能已很突出，但是其应用还主要停留在轻质导线、超级电容器、驱动器等简单器件领域，其结构设计、性能发挥和应用开发还远远不够，因此进一步拓展石墨烯基一维宏观结构，优化其性质，探索其应用具有重要的研究价值与意义。基于此，本研究受天然洋葱茎养分传输机制启发，发展了一种新型通用的水热辅助湿纺组装法，首次获得了系列的可膨胀、多褶皱、仿葱卷结构的石墨烯基微米棒，以这种独特结构的石墨烯微米棒为一维碳框架，实现了锂金属的在微米棒3D空间内的定向吸附、存储与利用，有效抑制了锂枝晶的生长，并结合瞬态吸附、实时吸附等原位表征手段，揭示了其内在吸附机制。此外，该方法亦可以实现对各类正极微纳米材料的高含量负载，制备的石墨烯/磷酸铁锂复合微米棒（~86 wt.%），展现了卓越的倍率性能与循环稳定性。该工作为进一步发挥石墨烯及其宏观一维纳米组装体独特的结构和性能优势，探索并拓宽其应用提供了新的思路。