Deciphering the Competing Mechanisms of Li Microstructure Formation in Solid Electrolytes with Nuclear Magnetic Resonance Spectroscopy (NMR) and Imaging (MRI)

利用核磁共振波谱 (NMR) 和成像 (MRI) 解读固体电解质中锂微结构形成的竞争机制

• 批准号: 2319151
• 负责人: Yan-Yan Hu
• 金额: $ 47.91万
• 依托单位: Florida State University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2024
• 资助国家: 美国
• 起止时间: 2024-01-15 至 2026-12-31
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2319151&HistoricalAwards=false
• 关键词: Deciphering; Competing; Mechanisms; Li; Microstructure; Deciphering; Competing; Mechanisms; Li; Microstructure

PART 1: NON-TECHNICAL SUMMARY This project tackles a critical challenge in battery technology that is widely used daily: the formation of tiny structures, called dendrites, within batteries. These dendrites can cause short circuits, limiting the power and lifespan of solid-state batteries, which are crucial for powering a sustainable energy future. The team aims to understand how these dendrites form and develop mitigating strategies. The research focuses on Li7La3Zr2O12 (LLZO), an important component in solid-state batteries. By using advanced techniques like nuclear magnetic resonance (NMR) and magnetic resonance imaging (MRI), the team hopes to uncover the root causes of dendrite formation. This understanding is vital for designing batteries with longer lifespans and higher efficiency.The outcomes of this research will enhance our understanding of battery technology and contribute to developing more efficient and sustainable energy storage solutions, directly benefiting society at large. The project also aims to develop new tools to study a broad range of functional materials, contributing to scientific knowledge in multiple fields. Moreover, it will establish a new course on advanced magnetic resonance techniques and broaden the participation of underrepresented groups in scientific research via several educational and outreach platforms. By addressing the major challenges associated with rechargeable batteries, this project will promote the progress of science and technology and advance the national welfare. PART 2: TECHNICAL SUMMARYLi microstructure formation in solid electrolytes results in battery short circuits, limiting the power density and lifespan of all-solid-state batteries (ASSBs). Unlike extensively studied liquid systems, dendrite formation in solids is complex and challenging to characterize. This project proposes two mechanisms for dendrite formation in solid electrolytes: non-uniform Li plating at the electrode-electrolyte interface (Mechanism 1) and reduction of Li+ ions at grain boundaries within solid electrolytes (Mechanism 2). While Mechanism 1 has been explored using electron and optical microscopy, Mechanism 2 remains less understood due to challenges in noninvasively probing bulk solids. To address this, the proposal employs nuclear magnetic resonance spectroscopy (NMR) and imaging (MRI) techniques. Specifically, the project aims to determine the source of Li dendrites using tracer-exchange NMR, create 3D images of dendrites within solid electrolytes using noninvasive 7Li/6Li MRI, and monitor real-time dendrite formation using in situ NMR and MRI, complemented by electron paramagnetic resonance studies. The chosen material system, Li7La3Zr2O12 (LLZO) and its derivatives represent a prominent oxide-based solid electrolyte with known dendrite formation issues. The research aims to distinguish between the proposed mechanisms and determine the dominant one with spatial and temporal resolution under varied conditions relevant to ASSB electrochemical cycling. Investigations on LLZO derivatives with diverse electronic conductivities will provide insights into the role of electronic conductivity in determining dendrite formation mechanisms and their distribution. The outcomes of this work will contribute to understanding and mitigating dendrite-related challenges, ultimately advancing the development of safer and more efficient solid-state batteries.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.

第1部分：非技术摘要该项目在每天广泛使用的电池技术中面临着一个关键的挑战：在电池内形成的小结构（称为树突）。这些树突可能会导致短路，从而限制了固态电池的功率和寿命，这对于为可持续能源的未来供电至关重要。该团队旨在了解这些树突如何形成并制定缓解策略。该研究的重点是LI7LA3ZR2O12（LLZO），这是固态电池中重要组成部分。通过使用先进的技术，例如核磁共振（NMR）和磁共振成像（MRI），该团队希望发现树突形成的根本原因。这种理解对于设计具有更长寿命和较高效率的电池至关重要。这项研究的结果将增强我们对电池技术的理解，并有助于开发更有效，更可持续的能源存储解决方案，从而直接使社会受益。该项目还旨在开发新的工具来研究广泛的功能材料，从而有助于多个领域的科学知识。此外，它将建立一门有关高级磁共振技术的新课程，并通过几个教育和外展平台扩大代表性不足的小组在科学研究中的参与。通过解决与可充电电池相关的主要挑战，该项目将促进科学和技术的进步，并促进国家福利。 第2部分：固体电解质中的技术摘要微观结构形成导致电池短路，从而限制了全稳态电池的功率密度和寿命（ASSBS）。与广泛研究的液体系统不同，固体中的树突形成是复杂的，而且表征挑战。该项目提出了两种在固体电解质中形成的树突形成的机制：在电极 - 电解质界面上的非均匀LI板（机理1）和固体电解质内晶界处的Li+离子的还原（机构2）。虽然已经使用电子和光学显微镜探索了机理1，但由于非侵入性探测大量固体的挑战，机理2的理解程度较低。为了解决这个问题，该提案采用核磁共振光谱（NMR）和成像（MRI）技术。具体而言，该项目旨在使用示踪剂 - 交换NMR来确定Li树突的来源，使用非侵入性7LI/6LI MRI在固体电解质中创建树突的3D图像，并使用Electon paragagnetic Resonance研究互补，并使用原点NMR和MRI监测实时树突形成。所选的材料系统Li7la3ZR2O12（LLZO）及其衍生物代表具有已知树突形成问题的杰出氧化物固体电解质。该研究旨在区分所提出的机制，并在与ASSB电化学循环相关的各种条件下以空间和时间分辨率来确定具有空间和时间分辨率的机制。对具有不同电子电导率的LLZO衍生物的研究将提供有关电子电导率在确定树突形成机制及其分布中的作用的见解。这项工作的结果将有助于理解和缓解与树突相关的挑战，最终提高更安全，更有效的固态电池的发展。该奖项反映了NSF的法定任务，并被认为是值得通过基金会的知识分子优点和更广泛的影响审查标准来通过评估来支持的。