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CAREER: Electro-Chemo-Mechanics of Li and Na Metal: Toward Dendrite- and Damage-Free Metallic Anodes of Rechargeable Batteries

职业：锂和钠金属的电化学力学：研究可充电电池的无枝晶和无损伤金属阳极

基本信息

批准号：
1944674
负责人：
George Pharr V
金额：
$ 55.67万
依托单位：
Texas A&M Engineering Experiment Station
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：
2020-06-01 至 2025-05-31
项目状态：
未结题

来源：
https://www.nsf.gov/awardsearch/showAward?AWD_ID=1944674&HistoricalAwards=false
关键词：
CAREER Electro Chemo Mechanics Li

项目摘要

Non-Technical Summary:Rechargeable batteries are everywhere in daily life. Indeed, lithium-based batteries have become the power source of choice in portable electronics and electric vehicles. Still, commercial batteries utilize materials with relatively low energy densities; they add substantial weight to vehicles and occupy huge volumes in portable electronics but must be re-charged every few hours. Owing to their enormous energy densities, batteries 'beyond lithium-ion' based on metallic lithium and sodium have emerged, primed to meet growing demands. However, these systems suffer from severe issues of degradation and safety that have precluded their practical use. Materials and mechanics-based studies are thus necessary to enable safe and durable operation. Accordingly, the goal of this project is to provide understanding of the interplay between functional and structural behavior of lithium and sodium metal anodes, combined with materials discovery of alloys. These studies will guide appropriate charging conditions, applied pressures, and material properties that prevent damage. Overall, advances in batteries will benefit the USA by reducing harmful emissions, improving safety, enhancing infrastructure, and securing energy independence. Commercializing lithium anodes would dramatically increase energy densities (up to ~4x) of portable electronics and electric vehicles, while commercializing sodium anodes may enable grid-scale storage of renewable energy. The broader objectives of this proposal include leveraging established programs to provide research experiences for military veterans and underrepresented minorities. The project will also develop immersive augmented/virtual reality (AR/VR) learning modules to enhance students’ understanding of the interplay among mechanics, microstructure, chemistry, and electric fields in materials for energy storage and conversion. Outreach activities will involve K-12 students and teachers to increase awareness of clean energy technologies.Technical Summary:While the electrochemistry of lithium and sodium has received extensive study, at the heart of the issues outlined above lies a mechanics of materials problem: unstable deformation occurs during operation, producing dendrites and damage. Complicating this matter is that due to their extreme chemical reactivity in air, relatively little is known regarding even the basic mechanical properties of lithium and sodium, e.g., sodium’s room temperature plastic properties and deformation mechanisms remain largely unknown. Even less is known regarding stresses developed during electrodeposition, time/temperature-dependent behavior, fracture and fatigue behavior, how alloys modify properties, and their corresponding influence on microstructural stability. This project will fill in these gaps in fundamental knowledge through testing the following hypotheses: (1) time-dependent plastic deformation dominates the mechanical behavior of lithium and sodium metal; (2) specific alloys enhance creep resistance, promoting structural stability; (3) stresses develop during electrodeposition that can damage surrounding layers and the metals themselves; and (4) pre-loads applied to electrode stacks promote microstructurally stable deposition. To test these hypotheses, this project will utilize unique experimental facilities and develop theoretical models to connect the evolution of mechanical properties, stress, and deformation to chemical and microstructural changes during electrochemical cycling. From the educational perspective of this proposal, textbooks seldom cover coupled phenomena in electro-chemo-mechanics. This project will develop AR/VR modules to fill these voids, which will be integrated into undergraduate/graduate curricula, shown at K-12 outreach activities, shared with K-12 teachers, and made available online. This project will also enable students in materials and mechanics to work in areas not conventionally open to the discipline (electrochemistry) to encourage interdisciplinary research careers.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.

非技术总结：可充电电池在日常生活中无处不在。事实上，锂电池已经成为便携式电子产品和电动汽车的首选电源。尽管如此，商用电池使用的材料能量密度相对较低；它们大大增加了车辆的重量，在便携式电子产品中占据了巨大的体积，但必须每隔几个小时充电一次。由于其巨大的能量密度，基于金属锂和钠的“超越锂离子”电池已经出现，准备好满足日益增长的需求。然而，这些系统存在严重的退化和安全问题，妨碍了它们的实际使用。因此，基于材料和力学的研究是必要的，以实现安全和持久的操作。因此，本项目的目标是提供对锂和钠金属阳极功能和结构行为之间相互作用的理解，并结合合金材料的发现。这些研究将指导适当的充电条件、施加的压力和防止损坏的材料特性。总的来说，电池的进步将通过减少有害排放、提高安全性、加强基础设施和确保能源独立而使美国受益。锂阳极的商业化将大大提高便携式电子设备和电动汽车的能量密度（高达4倍），而钠阳极的商业化可能使可再生能源的电网规模存储成为可能。该提案的更广泛目标包括利用现有项目为退伍军人和未被充分代表的少数民族提供研究经验。该项目还将开发沉浸式增强/虚拟现实（AR/VR）学习模块，以增强学生对能量存储和转换材料中力学、微观结构、化学和电场之间相互作用的理解。外展活动将涉及K-12年级的学生和教师，以提高对清洁能源技术的认识。技术概述：虽然锂和钠的电化学已经得到了广泛的研究，但上述问题的核心是材料力学问题：在操作过程中会发生不稳定变形，产生枝晶和损坏。更复杂的是，由于它们在空气中的极端化学反应性，人们对锂和钠的基本机械性能知之甚少，例如，钠的室温塑性性能和变形机制在很大程度上仍然未知。关于电沉积过程中产生的应力、时间/温度依赖行为、断裂和疲劳行为、合金如何改变性能以及它们对微观结构稳定性的相应影响，我们所知的就更少了。本项目将通过测试以下假设来填补这些基础知识的空白：(1)随时间变化的塑性变形主导了锂和钠金属的力学行为；(2)特定合金增强抗蠕变能力，促进结构稳定性；(3)电沉积过程中产生的应力会破坏周围层和金属本身；(4)施加在电极堆上的预载荷促进了微结构稳定的沉积。为了验证这些假设，该项目将利用独特的实验设备并开发理论模型，将电化学循环过程中机械性能、应力和变形的演变与化学和微观结构变化联系起来。从这一建议的教育角度来看，教科书很少涉及电化学力学中的耦合现象。该项目将开发AR/VR模块来填补这些空白，这些模块将整合到本科/研究生课程中，在K-12外展活动中展示，与K-12教师共享，并在网上提供。该项目还将使材料和力学专业的学生能够在传统上不向该学科开放的领域（电化学）工作，以鼓励跨学科的研究事业。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。