GOALI - Collaborative Research: Chemically Induced Stresses and Degradation Mechanisms in Ceramic Materials for Li Ion Batteries

非技术描述：该项目重点研究锂电池中使用的许多氧化物材料上形成的表面损伤层。大部分研究旨在了解这些层的形成，并制定能够缓解电池材料中相关降解机制的策略。该项目的具体发现将有助于延长用于各种应用的锂电池的寿命。通过Goali合作伙伴(通用汽车)，这项工作将直接为零排放电动汽车高能量密度锂离子电池改进电极的工业研究做出贡献。知识转移通过公开传播和与通用汽车研究人员的直接互动两种方式进行。技术细节：许多可能提高锂电池性能的电池材料都是陶瓷材料，其中表面损伤层(SDL)会造成严重的限制。例如，在层状阴极颗粒上形成表面膜的化学和电化学引起的结构变化会导致阻抗的大幅上升和循环寿命的限制--以至于SDL使这些材料在循环后无法使用。在所有这些表面薄膜中，重要的是要认识到各种因素会导致显著的机械应力，其中相应的弹性能量与化学和结构变化相互作用，这在大多数先前的研究中没有得到解决。需要发展关于SDL和表面涂层中的化学机械效应的基本知识是拟议研究的主要动机。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，缺陷耦合、多组分扩散等)。这些数据的解释依赖于在密歇根州立大学原子尺度模拟的基础上建立多尺度模型。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。通过与行业合作者的这些直接互动，所产生的新知识将被应用于商业上可行的系统。该奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

NON-TECHNICAL DESCRIPTION: This project focuses on surface damage layers that form on many of the oxide materials that are used in lithium-based batteries. Most of the research is designed to understand the formation of these layers, and to create strategies that can mitigate related degradation mechanisms in battery materials. The specific findings from this project will help to increase the lifetime of lithium-based batteries that are used in a variety of applications. Through the GOALI partner (General Motors), the work will contribute directly to industrial research on improved electrodes for high energy density lithium ion batteries for electric vehicles with zero emission. Knowledge transfer is occurring through both public dissemination and direct interactions with researchers at General Motors. TECHNICAL DETAILS: Many of the battery materials that can potentially improve the performance of lithium-based batteries are ceramics where surface damage layers (SDLs) cause serious limitations. For example, chemically and electrochemically induced structural changes that form surface films on layered cathode particles lead to substantial impedance rise and limited cycle life - to the extent that SDLs render these materials unusable after cycling. In all of these surface films, it is important to realize that a variety of factors lead to significant mechanical stresses, where the corresponding elastic energies interact with chemical and structural changes in ways that have not been addressed in most prior research. The need to develop fundamental knowledge about chemo-mechanical effects in SDLs and surface coatings is the primary motivation for the proposed research. 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 coupling, multicomponent diffusion, etc.). Interpretation of these data relies on building multiscale models informed by atomic scale simulations 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. Via these direct interactions with industrial collaborators, the resulting new knowledge will be applied to commercially viable systems.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.