CAREER: In Situ Nanomechanics of High-Performance Anode Materials for Sodium-Ion Batteries

该项目将描述钠离子电池电极材料的纳米力学和电化学相互作用，并开发本构模型来阐明这些材料的形态和结构演化。作为最广泛的储能技术之一，锂离子电池在过去的二十年里受到了密集的研究。钠离子电池被认为是一种低成本的替代品，因为钠的地球资源比锂丰富得多，而且受地理条件的限制也比锂小得多。然而，在理解高性能电极材料的机理方面，一个尚未探索的重大差距阻碍了先进钠离子电池的发展。这项拟议的研究跨越了几个学科，包括力学、材料科学、物理和电化学。本研究取得的基础性认识将对这些学科产生深远的影响。这项多学科的工作将培养具有广泛技能和知识的本科生和研究生，并让他们接触到实验和建模的互补研究。这项研究还将通过佐治亚理工学院的各种推广计划，让K-12年级的教师和学生参与，特别是女性和少数族裔。研究成果将被整合到一门新的固体力学实验课程的实验模块中。钠离子电池电极的储能和释放涉及一系列复杂的机械和电化学过程，包括变形、应力产生、质量传递、相变和化学反应。要实现钠离子电池技术的突破，需要对其机理及其与其他物理现象的强烈耦合有基本的了解。该奖项的研究目标是开发一种用于钠离子电池电极材料本构特性的原位纳米机械测试平台。该实验框架将用于研究钠离子电池中两种很有前途的高性能负极材料--钠化/脱盐锗/脱氧锗锡合金的原位力学性能。来自实验测量的空间和时间分辨本构行为将被合并到一个连续计算模型中，用于预测固体电极材料的力学退化和形态演变。

This Faculty Early Career Development (CAREER) Program project will characterize the nanomechanical and electrochemical interactions in sodium-ion battery electrode materials and develop constitutive models to elucidate the morphological and structural evolution in these materials. As one of the most widespread technologies for energy storage, lithium-ion batteries have been under intense studies over the past two decades. Sodium-ion batteries are being considered as a low-cost alternative because sodium is much more earth abundant and less geographically constrained than lithium. However, the development of advanced sodium-ion batteries has been hindered by a significant unexplored gap in understanding the mechanics of high-performance electrode materials. The proposed research spans several disciplines, including mechanics, materials science, physics, and electrochemistry. The fundamental understanding obtained in this research will make a profound impact on these disciplines. The multidisciplinary work will train undergraduate and graduate students with a broad range of skills and knowledge, and expose them to the complementary research of experimentation and modeling. The research will also involve K-12 teachers and students, particularly females and minorities, through various outreach programs at the Georgia Institute of Technology. The research results will be integrated into the lab modules of a new course on experimental solid mechanics.Energy storage and release of sodium-ion battery electrodes involves a complex set of mechanical and electrochemical processes, including deformation, stress generation, mass transport, phase transformation, and chemical reaction. A fundamental understanding of the mechanics and its strong coupling with other physical phenomena is required to achieve breakthroughs in the sodium-ion battery technology. The research objective of this award is to develop an in situ nanomechanical testing platform for the constitutive characterizations of sodium-ion battery electrode materials. The experimental framework will be employed to investigate the in situ mechanics of sodiated/desodiated germanium and germanium-tin alloys, which are two promising high-performance anode materials for advanced sodium-ion batteries. The space- and time-resolved constitutive behaviors from experimental measurements will be incorporated into a continuum computational model for predictive simulations of the mechanical degradation and morphological evolution in solid electrode materials.