GOALI - Collaborative Research: Chemically induced stresses and degradation mechanisms in ceramic materials for Li ion batteries

非技术描述：该项目侧重于在锂基电池中使用的许多氧化物材料上形成的表面损伤层。大多数研究旨在了解这些层的形成，并制定策略，以减轻电池材料的相关降解机制。这个项目的具体发现将有助于增加各种应用中使用的锂基电池的寿命。通过GOALI合作伙伴（通用汽车），这项工作将直接促进零排放电动汽车高能量密度锂离子电池电极改进的工业研究。通过公共传播和与通用汽车研究人员的直接互动，知识转移正在发生。技术细节：许多可能提高锂基电池性能的电池材料是陶瓷，其表面损伤层（sdl）造成了严重的限制。例如，化学和电化学诱导的结构变化会在层状阴极颗粒上形成表面膜，导致阻抗大幅上升和循环寿命有限，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导致显著的机械应力，其中相应的弹性能与化学和结构变化相互作用，而这些变化在大多数先前的研究中尚未得到解决。需要发展sdl和表面涂层的化学机械效应的基本知识是提出研究的主要动机。布朗大学的努力采用精确的应力原位测量以及其他实验方法来开发新方法，用于探测各种复杂现象，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）。对这些数据的解释依赖于建立多尺度模型，这些模型由密歇根州立大学的原子尺度模拟提供信息。两所大学的学生和教师直接与吴琰博士和通用汽车的其他研究人员合作，以扩大教育成果和加强知识向工业转移的方式。通过这些与工业合作者的直接互动，由此产生的新知识将应用于商业上可行的系统。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。

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.