Collaborative Research: Understanding Relationships Between Synthesis, Structure, Solid-State Electrochemistry, and Phase Stability in Clathrates and Related Materials

合作研究：了解包合物和相关材料的合成、结构、固态电化学和相稳定性之间的关系

基本信息

批准号：
2004514
负责人：
Candace Chan
金额：
$ 28.5万
依托单位：
Arizona State University
依托单位国家：
美国
项目类别：
Continuing Grant
财政年份：
2020
资助国家：
美国
起止时间：
2020-07-01 至 2024-06-30
项目状态：
已结题

来源：
https://www.nsf.gov/awardsearch/showAward?AWD_ID=2004514&HistoricalAwards=false
关键词：
Collaborative Research Understanding Relationships Between

项目摘要

NON-TECHNICAL DESCRIPTION:Clathrates are a class of materials with cage-like structures that can naturally hold guest ions, a feature that may be exploited for energy storage in rechargeable batteries. However, more research is needed to understand how the structure of the clathrate affects ion migration and the durability of the material under repeated electrochemical cycling. Through this collaborative project, supported by the Solid State and Materials Chemistry program in the Division of Materials Research at NSF, researchers at Arizona State and University of Delaware jointly identify structural features of the clathrates that promote fast ion diffusion and develop new approaches to synthesize these materials. Thereby they gather new knowledge connecting the structural effects of clathrates and related compounds to their physical, electrochemical, and materials chemistry properties. The fundamental science gained from these studies could have far reaching impacts in other fields where these materials have potential applications, such as superconductors, thermoelectrics, optoelectronics, magnets, and photovoltaics. Additionally, this collaboration between two universities and three different departments (materials science, chemistry, and physics) exposes students to multidisciplinary research. Outreach and educational activities also engage students and provide interdisciplinary training and immerse them into areas outside their immediate field of expertise. TECHNICAL DESCRIPTION:This collaborative project, supported by the Solid State and Materials Chemistry program in the Division of Materials Research at NSF, identifies structural features that lead to fast ion diffusion and obtain better understanding of electrochemically driven phase transformations in Li-Tetrel (Tt) systems, particularly for clathrates and other open framework structures. The specific objectives of the research are to: (1) Understand the structural parameter space for Tt (Tt = Si, Ge, Sn) clathrate and clathrate-like materials with high ionic mobility; (2) Re-map the phase space of Li-Tt systems, including non-equilibrium phases, coupled with studies on understanding the ionic transport within these phases, and (3) Use electrochemistry to inform solid-state synthesis and vice versa, to enable new synthetic approaches for clathrates and related materials that are either intermediates in the lithiation pathways or can be used as precursors for the synthesis steps. Through a concerted approach combining the synthetic, structural and electrochemical characterization, and theoretical expertise of the PIs, this work furthers the electrochemical understanding of clathrate materials, leading to new insights on structural features that result in fast diffusion pathways, low ion migration barriers, and phase stability. Novel synthetic approaches combining high temperature coulometric titration and low temperature flux methods are used to trap kinetic/metastable phases and controllably synthesize high quality single-crystalline materials. Isostructural compounds containing key Li local environments are employed as model compounds to understand the ion (de)insertion processes in Li-Tt binary (and ternary/quaternary) compounds, with an emphasis on Tt = Ge. By means of a unique feedback loop connecting electrochemistry and synthesis, information about phases formed during electrochemical lithiation is used to design novel precursors for synthesis of clathrates, and solid-state reactions using chemical oxidation are adapted to develop electrochemical synthesis methods with finer control over composition. Synchrotron X-ray studies are used to characterize the local and crystalline structures and phase evolution during electrochemical reaction and/or synthesis. In all cases, density functional theory calculations support experimental findings and guide materials design, particularly by identifying formation energies and ionic transport mechanisms.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

非技术描述：外墙是一类具有笼子状结构的材料，可以自然容纳客人离子，这是一种可以利用用于可充电电池的能量存储的功能。但是，需要进行更多的研究来了解杂质的结构如何影响离子迁移以及在重复的电化学循环下材料的耐用性。通过这个合作项目，在NSF材料研究部的固态和材料化学计划的支持下，亚利桑那州立大学的研究人员和特拉华大学共同确定了围墙的结构性特征，这些特征促进了快速离子扩散并开发了合成这些材料的新方法。因此，他们收集了新的知识，将外酸盐和相关化合物的结构效应与它们的物理，电化学和材料化学特性联系在一起。从这些研究中获得的基本科学可能会在这些材料具有潜在应用的其他领域产生遥远的影响，例如超导体，热电学，光电子，磁铁和光伏电源。此外，两所大学和三个不同系（材料科学，化学和物理学）之间的合作使学生接受了多学科研究。外展和教育活动还吸引学生，并提供跨学科的培训，并将其沉浸在其直接专业领域之外的领域。技术描述：该协作项目得到了NSF材料研究部的固态和材料化学计划的支持，它确定了导致快速离子扩散的结构特征，并更好地了解LI-Tetrel（TT）系统中电化学驱动的相位转换，尤其是在覆盖物和其他开放式框架结构中。该研究的特定目标是：（1）了解具有高离子迁移率的TT（TT = Si，ge，Sn）的结构参数空间；（2）重新映射Li-TT系统的相空间，包括非平衡阶段，再加上了解这些阶段内离子传输的研究，（3）使用电化学来告知固态合成，副合成，以启用新的合成方法，以使其在LITHERITION中使用中间人的综合材料，或者可以作为综合途径。通过结合PIS的合成，结构和电化学表征以及理论专业知识的一致方法，这项工作进一步扩大了对围层材料的电化学理解，从而导致对结构特征的新见解，从而导致快速扩散途径，低离子迁移障碍，低离子迁移障碍和相位稳定性。新型的合成方法结合了高温库米滴定和低温通量方法用于捕获动力学/可稳态相，并可以控制地合成高质量的单晶材料。含有关键LI局部环境的同源化合物被用作模型化合物，以了解Li-TT二进制（和三元/季元）化合物中的离子（DE）插入过程，并强调TT = GE。通过连接电化学和合成的独特反馈循环，有关在电化学静态过程中形成的相的信息用于设计用于合成外壳的新型先驱，并且使用化学氧化的固态反应进行了调整以开发具有分别控制剂控制的拟剂控制的电化学合成方法。同步加速器X射线研究用于表征电化学反应和/或合成过程中局部和晶体结构以及相位演变。在所有情况下，密度功能理论计算都支持实验发现和指导材料设计，尤其是通过识别形成能和离子运输机制。该奖项反映了NSF的法定任务，并被认为是通过基金会的智力优点和更广泛影响的审查标准来评估值得通过评估来支持的。