Elucidating the Impact of Electrostatic Interactions and Number of Layers on the Mechanisms of Ion Intercalation on Graphene Electrodes

石墨烯是一种具有新兴电化学性能的原子薄材料。在固态和材料化学项目的支持下，该项目研究了其厚度的影响，以及它所能实现的独特材料相互作用，对石墨烯在其结构中插入离子的能力的影响，从而应用于电能存储。该项目的科学影响包括产生新的知识，使使用简单的化学效应能够提高电池电极的能量密度和稳定性。综合研究、教育和推广计划为本科生和K-12学生提供学习机会。活动包括电化学教学的现代化及其通过社交媒体的传播，通过“电化学训练营”对能源材料进行直接的实验室指导，以及通过学生组织组织的外展活动。研究小组利用其对西班牙裔人口的认同和研究群体的多样性，对科学学科中代表性不足的群体的教育、包容和保留产生影响。这些小组将接触到尖端的科学，使用最先进的表征设备和先进的计算工具。技术摘要：本研究旨在阐明石墨烯的原子厚度对离子嵌入机制的影响，并探讨其薄体上的本地和外部静电相互作用如何改变嵌入过程的能量学和速率。该项目考虑了以下目标和方法：(1)通过微纳米加工控制层数和界面静电相互作用，首次实现了非水离子在明确定义的石墨烯电极上的插层电化学系统研究；(2)利用原位中子反射法、透射电子显微镜和电化学显微镜方法，对碱性离子在少数层石墨烯上的插层机理和表面修饰的影响有了新的认识；(3)利用密度泛函理论定量地理解静电和电子相互作用的能量分量及其与创新力场项的耦合。通过这项活动产生的知识可以使用简单的静电效应来调整离子插入的能量，潜在地改善电能存储的条件，并在静电效应与离子界面和体反应机制之间建立广泛的相关性，这些相关性可扩展到其他2d材料。

Non-Technical AbstractGraphene is an atomically-thin material with emerging electrochemical properties. With the support of the Solid State and Materials Chemistry program, this project studies the impact of its thickness, and the unique materials interactions it enables, on graphene's ability for inserting ions into its structure for applications in electrical energy storage. The scientific impact of this project consists of generating new knowledge that enables the use of simple chemical effects to improve the energy density and stability of battery electrodes. The integrated research, educational and outreach plan addresses learning opportunities for undergraduate and K-12 students. Activities include the modernization of electrochemical instruction and its diffusion through social media, direct laboratory instruction on energy materials through the "electrochemical bootcamp," and outreach activities organized through student organizations. The research team makes use of its identification with the Hispanic population and research group diversity to make an impact in the education, inclusion and retention of underrepresented groups in scientific disciplines. These groups will be exposed to cutting-edge science, using state-of-the-art characterization facilities and advanced computational tools.Technical AbstractThe research activity aims at elucidating the impact of graphene's atomic thickness in determining the mechanisms of ion intercalation, and to explore how native and external electrostatic interactions across its thin bulk modify the energetics and rate of intercalation processes. This project contemplates the following goals and approaches: (1) implementing the first electrochemical systematic study of non-aqueous ion intercalation on well-defined graphene electrodes by controlling the number of layers and interfacial electrostatic interactions via micro- and nanofabrication, (2) using in situ neutron reflectometry, transmission electron microscopy, and electrochemical microscopy methods to yield new insights into the intercalation mechanisms of alkaline ions on few layer graphene and the effects of surface modifications, and (3) using density functional theory for understanding quantitatively the energetic components of the electrostatic and electronic interactions and its coupling to innovative force field terms. The knowledge generated by this activity enables the use of simple electrostatic effects for tuning the energetics of ion insertion, potentially improving conditions for electrical energy storage, and establishing broad correlations between electrostatic effects and ionic interfacial and bulk reaction mechanisms that are extendable to other 2D-materials.