Probing ionic diffusion in battery materials using NMR

使用 NMR 探测电池材料中的离子扩散

• 批准号: 2596740
• 金额: --
• 依托单位: University of Oxford
• 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-2596740
• 关键词: Probing; ionic; diffusion; battery; materials

This project falls within the EPSRC Physical Sciences and Energy research areas.The need for better batteries has never been greater. Due to their high energy densities, lithium ion batteries have revolutionised consumer electronics and are playing a central role in the electrification of transport. In order to support the transition to renewable energy sources and as the automotive sector becomes fully electric, new high-performing materials will be needed. In order to meet this demand, new materials are required for use in Li-ion cells but also for the development of new technologies such as all solid-state batteries. For example, solid electrolytes make the use of a lithium metal anode possible, significantly increasing the energy density. Understanding ionic diffusion in these materials is key to tuning compositions, developing new materials and enabling new battery technologies. The development of a comprehensive physical picture of ion transport is challenging because in any one material ion transport crosses a large range of time and length scales. Ion transport is divided into microscopic and macroscopic levels, where the macroscopic processes consist of a series of microscopic events. Microscopic processes can be probed using variable-temperature nuclear magnetic resonance spectroscopy (NMR) and NMR relaxometry, however, these techniques are unable to review the long-range lithium diffusion. Pulsed-field gradient (PFG) NMR allows the measurement of macroscopic ionic diffusion through solid materials. PFG is nuclei specific and can therefore provide information about each of the ion's contributions. This technique is highly informative and complementary to Electrochemical Impedance Spectroscopy (EIS). When PFG and EIS can be used successfully in tandem, the mobile ion concentration can be estimated.This project will involve technique development to enable data collection and analysis to be carried out on a range of battery materials. PFG NMR will be used to measure diffusion coefficients, activation energies and estimate conductivities of a range of important battery materials, such as solid electrolytes. Alongside NMR, a number experimental techniques will be used to provide complementary data. Electrochemical cycling and techniques, such as EIS, will be used to investigate performance. Techniques, including diffraction, microscopy and tomography will provide additional structural data to support models.The project is co-funded by Johnson Matthey as part of an iCASE studentship.

该项目属于 EPSRC 物理科学和能源研究领域。对更好电池的需求从未如此强烈。由于其高能量密度，锂离子电池彻底改变了消费电子产品，并在交通电气化中发挥着核心作用。为了支持向可再生能源的过渡以及随着汽车行业实现完全电动化，将需要新的高性能材料。为了满足这一需求，不仅需要在锂离子电池中使用新材料，还需要开发全固态电池等新技术。例如，固体电解质使锂金属阳极的使用成为可能，从而显着提高了能量密度。了解这些材料中的离子扩散是调整成分、开发新材料和实现新电池技术的关键。开发离子传输的全面物理图像具有挑战性，因为在任何一种材料中，离子传输都会跨越大范围的时间和长度尺度。离子输运分为微观和宏观两个层面，宏观过程由一系列微观事件组成。可以使用变温核磁共振波谱 (NMR) 和 NMR 弛豫测量来探测微观过程，但是，这些技术无法检查长程锂扩散。脉冲场梯度 (PFG) NMR 可以测量固体材料中的宏观离子扩散。 PFG 是原子核特异性的，因此可以提供有关每种离子贡献的信息。该技术信息丰富，是电化学阻抗谱 (EIS) 的补充。当 PFG 和 EIS 能够成功地串联使用时，就可以估计移动离子浓度。该项目将涉及技术开发，以便能够对一系列电池材料进行数据收集和分析。 PFG NMR 将用于测量扩散系数、活化能并估计一系列重要电池材料（例如固体电解质）的电导率。除了核磁共振之外，还将使用许多实验技术来提供补充数据。电化学循环和 EIS 等技术将用于研究性能。衍射、显微镜和断层扫描等技术将提供额外的结构数据来支持模型。该项目由庄信万丰 (Johnson Matthey) 共同资助，作为 iCASE 学生奖学金的一部分。