EAPSI: Characterizing energy storage in supercapacitors using atomically thin carbon sheets (Graphene)

目前储能技术面临的挑战不仅仅是电池和电容器。当应用程序需要同时处理大量能量并快速处理时，这些设备存在几个缺陷。超级电容器是一种潜在的解决方案，因为它们在功率和能量比较方面都具有很强的性能。超级电容器处理中等电量的灵活性比电池快，这使它们成为各种应用的理想选择。最近的研究表明，石墨烯是蜂窝状排列的单层碳，作为超级电容器的电极材料表现得特别好。该项目将探索石墨烯的行为，并将其行为从单层绘制到多层。这项研究将在国家同步加速器研究实验室与李嵩博士合作进行，只有通过那里展示的微调石墨烯生长能力才能实现。碳材料通常用作超级电容器的电极材料，而石墨烯由于其2D结构和巨大的比表面积而脱颖而出。然而，由于2D层之间的Van der Waals相互作用，石墨烯的合成很复杂，导致层聚集成块状材料。当系统从纳米尺度移动到宏观尺度时，行为发生了显著变化。通常使用的方法是机械地、化学地或通过液相剥离来将这些层剪切开。这些“自上而下”的过程往往在产品质量或数量上受到限制。样品将用隧道电子显微镜和X射线光电子显微镜进行表征。这项研究将允许使用循环伏安法、恒电流充放电和电化学阻抗谱准确地描绘器件的行为。NSF EAPSI奖由中国科技部资助。

Current challenges in energy storage technology require more than batteries and capacitors. These devices suffer from several deficiencies when applications require simultaneously handling large amounts of energy and doing so quickly. Supercapacitors are a potential solution due to their strong performance in both power and energy comparisons. The flexibility of supercapacitors to handle moderate amounts of energy faster than batteries makes them ideal for use in a variety of applications. Recent studies show graphene, a single layer of carbon in a honeycomb arrangement, performs particularly well as the electrode material for supercapacitors. This project will seek to explore the behavior of graphene and map the behavior from single to multilayer. This research will be conducted at the National Synchrotron Research Laboratory, in collaboration with Dr. Li Song and will only be made possible through the finely-tuned graphene growth capabilities exhibited there.Carbon materials are commonly used as the electrode material for the construction of supercapacitors, and graphene stands out as a strong candidate given its 2D structure and vast specific surface area. However, graphene synthesis is complicated due to the Van der Waals interactions between the 2D layers, causing layers to agglomerate into a bulk material. The behavior as the system moves from the nanoscale to the macroscale changes significantly. Often methods are used to shear these layers apart mechanically, chemically, or through liquid-phase exfoliations. These "top down' processes are often limited in product quality or quantity. Samples will be characterized with Tunneling Electron Microscopy and X-Ray Photoelectron Microscopy. This study will allow for the accurate mapping of the behavior of devices using Cyclic Voltammetry, Galvanostatic Charge-discharge, and Electrochemical Impedance Spectroscopy. This NSF EAPSI award is funded in collaboration with the Chinese Ministry of Science and Technology.