The Nanoscale Cryo-Microscopy of the Nucleation and Growth of Dendrites in Lithium-Ion Batteries

锂离子电池中枝晶的成核和生长的纳米级冷冻显微镜

• 批准号: 2791048
• 金额: --
• 依托单位: Imperial College London
• 依托单位国家: 英国
• 项目类别: Studentship
• 财政年份: 2021
• 资助国家: 英国
• 起止时间: 2021 至 无数据
• 项目状态: 未结题
• 来源: https://gtr.ukri.org/projects?ref=studentship-2791048
• 关键词: Nanoscale; Cryo; Microscopy; Nucleation; Growth

Internal short-circuits (ISC) are a major cause of failure in lithium-ion batteries and typically occur due to the dendrite formation, although the actual mechanism of the nucleation and growth of these microstructures is still not well understood. This is especially true at the nanoscale due to the limitations presented by current techniques, such as scanning electron microscopy (SEM). The purpose of this research project is to present the application of a new cryo-microscopy set-up, the Imperial Centre for the Cryo-Microscopy of Materials (I(CM)2), at Imperial College London. This has the capability of combining cryo-transmission electron microscopy (cryo-TEM) with cryo-atom probe tomography (cryo-APT) to study dendrite nucleation at a sub-atomic scale. When correlated, these techniques will provide information on the local chemistry, particularly degradation-related defects, and a highly resolved compositional mapping of the atomic arrangement, respectively, thus painting a clearer image of the dendrite nucleation mechanism than what is currently known. It is well known that lighter elements, such as hydrogen, carbon, lithium and sulphur, have been key in advancing battery technology as we know it. Yet, due to their susceptibility to beam damage and challenges associated with their quantification, there are clear limitations associated with the study of such elements. APT is a growing technology that exhibits nearly uniform capabilities in identifying even the lightest of elements, making it a high-potential candidate in its application to lithium-ion battery systems. Achieving an improved understanding of the local chemistry and structural variations, made possible with this workflow, associated with dendrite nucleation and evolution will improve our understanding of their mechanism and growth. These results will subsequently be crucial in devising dendrite-suppression measures and contributing to the development of next-generation LIBs. Industry and consumers will also benefit from an improved understanding of the root causes of ISCs, a key limitation in battery technology today and a challenge that researchers globally are committed to overcoming. This workflow will be used to investigate the effects of ambient temperature variation, electrolyte composition, excess current density and state of charge (SoC) on dendrite evolution and chemistry, which will also help to improve our understanding of the interplay of these factors on battery degradation. As this research project is one of the first to use this set-up, a crucial aspect will be developing a suitable protocol for the sample (electrode) preparation, transfer and characterisation. This information can then be used for subsequent projects, particularly those relating to energy materials, while the more general site-selective analysis techniques will be beneficial to a wider reach of scientists using cryo-methods.

内部短路（ISC）是锂离子电池失效的主要原因，并且通常由于枝晶形成而发生，尽管这些微结构的成核和生长的实际机制仍然没有很好地理解。由于扫描电子显微镜（SEM）等当前技术的局限性，在纳米尺度上尤其如此。本研究项目的目的是提出一个新的低温显微镜设置，帝国中心的材料低温显微镜（I（CM）2），在帝国理工学院伦敦的应用。这具有将低温透射电子显微镜（cryo-TEM）与低温原子探针断层扫描（cryo-APT）相结合以在亚原子尺度上研究枝晶成核的能力。当相关时，这些技术将分别提供关于局部化学的信息，特别是与降解相关的缺陷，以及原子排列的高分辨率组成映射，从而描绘出比目前已知的更清晰的枝晶成核机制的图像。众所周知，氢、碳、锂和硫等较轻的元素一直是推进电池技术的关键。然而，由于它们对束流损伤的敏感性以及与其量化相关的挑战，存在明显的局限性与这些元素的研究相关。APT是一种不断发展的技术，在识别最轻的元素方面表现出几乎一致的能力，使其成为锂离子电池系统应用的高潜力候选者。实现局部化学和结构变化的更好的理解，使这个工作流程成为可能，与枝晶成核和演变将提高我们对它们的机制和生长的理解。这些结果随后将是至关重要的设计枝晶抑制措施，并有助于下一代LIB的发展。工业和消费者也将受益于对ISC根源的更好理解，这是当今电池技术的一个关键限制，也是全球研究人员致力于克服的一个挑战。该工作流程将用于研究环境温度变化，电解质成分，过量电流密度和充电状态（SoC）对枝晶演变和化学的影响，这也将有助于提高我们对这些因素对电池退化的相互作用的理解。由于该研究项目是第一个使用该设置的项目之一，因此一个关键方面将是开发用于样品（电极）制备，转移和表征的合适协议。这些信息可用于随后的项目，特别是与能源材料有关的项目，而更一般的选址分析技术将有利于更广泛地接触使用低温方法的科学家。