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In-situ morphology characterization of self-assembled high-energy density mesoporous electrodes using x-ray and neutron scattering

使用 X 射线和中子散射对自组装高能量密度介孔电极进行原位形貌表征

基本信息

批准号：
1336057
负责人：
Bryan Vogt
金额：
$ 36.5万
依托单位：
University of Akron
依托单位国家：
美国
项目类别：
Standard Grant
财政年份：
2013
资助国家：
美国
起止时间：
2013-10-01 至 2017-09-30
项目状态：
已结题

来源：
https://www.nsf.gov/awardsearch/showAward?AWD_ID=1336057&HistoricalAwards=false
关键词：
situ morphology characterization self assembled

项目摘要

Nanoporous materials are attractive for electrochemical energy storage applications. For insertion battery electrodes, these pores provide improved morphological stability during charge-discharge cycles through accommodation of large volumetric changes. However, relationships between morphological structure and performance are still, in general, lacking; in particular, complex multi-component and multi-scale materials should enable significant improvements in performance. For example, carbon coating of metal oxides or silicon provides improved performance in comparison to graphite or pure metal oxide. This project seeks to provide a fundamental framework for the design and characterization of hybrid materials for Li insertion battery electrodes using well-defined model materials in conjunction with an in-situ multiscale (atomic and meso) characterization and testing program.Self-assembled ordered materials provide model electrodes to enable fundamental insight into how morphology evolution and distortion during cycling impacts long term battery capacity. In this work, we propose to use cooperative self assembly of phenolic resin (carbon precursor) and (1) sol-gel Li-doped vanadium pentoxide or (2) silicon nanoparticles to fabricate ordered mesoporous nanocomposites as model materials by which structure-property relationships can be elucidated. This self-assembly route enables near monodisperse pore sizes, wall thickness and transport paths for fundamentally examining the impact of pore size and nanoparticle (Li-V2O5 or Si) content on the performance of these nanocomposite materials as insertion battery electrodes. The nanocomposite matrix allows for significant incorporation of Li (through insertion in Li-V2O5 or Si) and high electrode conductivity (through continuous carbon pathways). The PI proposes to systematically vary the nanoparticle:carbon ratio and the nanoparticle size/sol aging to develop an improved understanding of morphology-property relationships, enhanced by their well-defined mesoscale structure. A suite of characterization tools (including TEM, porosimetry, and scattering) will enable correlation of structure to standard electrochemical performance tests. Of particular interest are structural changes involving swelling, de-swelling, and distortion under charge-discharge conditions that will be elucidated by in-situ grazing incidence small angle x-ray scattering and rotational small angle neutron scattering to address fundamental material challenges associated with electrode stability. Novel in-situ small angle scattering studies during electrochemical testing are proposed to elucidate solid-electrolyte interphase formation and potential routes to mitigate performance loss through nanostructuring and improved control of charge-discharge cycles. Combined these studies will provide improved basic understanding of structure-property relations for porous Li ion battery anodes and potentially provide new engineering solutions for high performance batteries.Advances in battery technology from improved fundamental understanding developed could lead to improved battery efficiency, battery usage in higher power applications and increased battery lifetime. Due to the growing utilization of Li insertion batteries in consumer and industrial applications, the potential impact from even modest advances in efficiency and lifetime is quite large. There are both economic and environmental benefits to consider as increased battery lifetime will decrease the replacement rate for batteries in applications, especially considering the growing market for batteries from consumer electronics to transportation. Dissemination of concepts associated with this research will be disseminated to a broader, public audience through partnership with UA-St. Vincent?s High School (STVM) and the Akron Global Polymer Academy (AGPA) that provides materials to K-12 teachers nationwide; additional local outreach effort will include trips to classrooms for grades 6-10, through AGPA connections.

纳米多孔材料对于电化学能量存储应用是有吸引力的。对于插入式电池电极，这些孔通过适应大的体积变化在充电-放电循环期间提供改进的形态稳定性。然而，形态结构和性能之间的关系仍然是，在一般情况下，缺乏;特别是，复杂的多组分和多尺度的材料应该能够显着提高性能。例如，与石墨或纯金属氧化物相比，金属氧化物或硅的碳涂层提供改进的性能。该项目旨在提供一个基本的框架，用于锂插入电池电极的混合材料的设计和表征，使用定义良好的模型材料结合原位多尺度（原子和介观）表征和测试程序。自组装有序材料提供模型电极，使人们能够从根本上了解循环过程中的形态演变和变形如何影响长期电池容量。在这项工作中，我们建议使用酚醛树脂（碳前体）和（1）溶胶-凝胶Li掺杂的五氧化二钒或（2）硅纳米颗粒的协同自组装来制备有序的介孔纳米复合材料作为模型材料，通过它可以阐明结构-性能关系。这种自组装途径能够实现接近单分散的孔径、壁厚和传输路径，用于从根本上检查孔径和纳米颗粒（Li-V2 O 5或Si）含量对这些纳米复合材料作为插入式电池电极的性能的影响。该纳米复合材料基质允许大量掺入Li（通过插入Li-V2 O 5或Si）和高电极电导率（通过连续的碳通路）。PI建议系统地改变纳米颗粒：碳比和纳米颗粒尺寸/溶胶老化，以提高对形态-性质关系的理解，并通过其定义明确的介观结构来增强。一套表征工具（包括TEM、孔隙率测定和散射）将使结构与标准电化学性能测试相关联。特别令人感兴趣的是结构变化，涉及膨胀，去膨胀，和变形下的充电-放电条件下，将阐明通过原位掠入射小角度X射线散射和旋转小角度中子散射，以解决与电极稳定性相关的基本材料的挑战。在电化学测试过程中，提出了新的原位小角散射研究，以阐明固体电解质界面的形成和潜在的途径，以减轻性能损失，通过纳米结构和改善控制的充电-放电循环。结合这些研究将提供对多孔锂离子电池阳极的结构-性能关系的更好的基本理解，并可能为高性能电池提供新的工程解决方案。电池技术的进步可能会导致电池效率的提高，电池在更高功率应用中的使用和电池寿命的延长。由于锂离子电池在消费和工业应用中的使用越来越多，即使在效率和寿命方面的微小进步也会产生相当大的潜在影响。这既有经济效益，也有环境效益，因为电池寿命的延长将降低应用中电池的更换率，特别是考虑到从消费电子到运输的电池市场不断增长。与本研究相关的概念传播将通过与UA-St. Vincent的合作传播给更广泛的公众受众。学校的高中（STVM）和阿克伦全球聚合物学院（AGPA），提供材料的K-12教师在全国范围内;额外的本地推广工作将包括前往教室6-10年级，通过AGPA连接。