GOALI - Collaborative Research: The Impact of Chemically Induced Stresses on Kinetic Processes and Degradation Mechanisms in Non-Stoichiometric Oxides

非技术描述：该研究项目集中在几种在能源相关应用中非常重要的氧化物材料上。人们感兴趣的中心现象与成分变化(例如，在电池材料中添加和移除锂)造成的内部应力有关。该项目的具体发现直接有助于开发用于混合动力汽车和电动汽车的高能量密度锂离子电池的改进电极，以及用于燃料电池和催化的改进材料。知识转移既通过公开传播，也通过与研究人员和通用汽车公司的直接互动进行。技术细节：在离子材料中，内应力、材料中的缺陷、电化学现象和动力学过程(如扩散和相变)之间存在复杂的相互作用。这些压力导致了正在探索的固体氧化物燃料电池和锂离子电池新材料的退化和性能限制。目前，对这些与压力相关的问题的科学理解非常有限。在这个项目中，对这些现象的研究是基于系统的和战略规划的调查，将理论和实验紧密结合在一起。布朗大学的工作使用了精确的现场应力测量以及其他实验方法来开发新的方法来探索各种复杂的现象，其中应力与基本机制的相互作用知之甚少(例如，缺陷关联、晶界偏析、多组分扩散等)。对这些数据的解释依赖于密歇根州立大学的原子尺度模型。两所大学的学生和教职员工正在与阎吾博士和通用汽车的其他研究人员直接合作，以扩大教育成果并加强向行业的知识转移。本项目对应力对动力学过程的影响和降解机制的全面理解也与更广泛的离子固体有关。

NON-TECHNICAL DESCRIPTION: This research project focuses on several oxide materials that are important in energy related applications. The central phenomena of interest are linked to internal stresses that are created by changes in composition (for example, adding and removing lithium in a battery material). The specific findings from this project are contributing directly to the development of improved electrodes for high energy density lithium ion batteries for hybrid and electric vehicles, and improved materials for applications in fuel cells and catalysis. Knowledge transfer is occurring through both public dissemination and direct interactions with researchers and General Motors. TECHNICAL DETAILS: In ionic materials there is a complex interplay between internal stresses, defects in the material, electrochemical phenomena and kinetic processes (e.g., diffusion and phase transformations). These stresses lead to degradation and performance limitations in new materials that are being explored for both solid oxide fuel cells and lithium ion batteries. Scientific understanding of these stress-related issues is currently very limited. In this project, research into these phenomena is based on systematic and strategically planned investigations that closely integrate theory and experiments. The efforts at Brown University employ precise in situ measurements of stresses along with other experimental methods to develop novel approaches for probing a variety of complex phenomena where stress interactions with fundamental mechanisms are poorly understood (e.g., defect association, grain boundary segregation, multicomponent diffusion, etc.). Interpretation of these data relies on atomic scale modeling at Michigan State University. Students and faculty from both Universities are working directly with Dr. Yan Wu and other researchers at General Motors, in ways that expand educational outcomes and enhance knowledge transfer to industry. The overall understanding of stress effects on kinetic processes and degradation mechanisms obtained from this project is also relevant to a broader range of ionic solids.