Collaborative Research: Chemomechanical Degradation of Oxide Cathodes in Li-ion Batteries: Synchrotron Analysis, Environmental Measurements, and Data Mining

非技术描述：充电电池是电动汽车和可再生能源整合的关键。陶瓷电极的机械退化是导致电池材料容量衰退的一个问题。尽管电池技术稳步发展，但对机械老化和失效机理的了解仍然滞后，这主要是由于电陶瓷化学的内在复杂性、结构/成分的异质性以及对环境和操作条件的敏感性。本项目旨在阐明陶瓷电池材料的老化机理。这项研究通过将新颖的实验和建模方法紧密结合在一起，创造了电池材料科学的基础知识。在教育方面，普渡大学、弗吉尼亚理工大学和SLAC国家加速器实验室之间的多方面合作为该项目的学生提供了独特的培训机会。将继续努力鼓励代表性不足的研究生和本科生加入该项目。与普渡大学的女性工程项目和弗吉尼亚理工大学的目标地区合作的外展工作将继续促进女性参与科学和工程。技术细节：该项目的首要目标是了解缺陷在界面或颗粒内的开始、积累和生长，以及缺陷-微结构-锂离子电池性能之间的相互关系，使用操纵面同步X射线分析技术、环境纳米压痕和数据挖掘。研究工作包括(I)使用同步加速器X射线分析技术来表征多个长度尺度上的局部氧化还原反应、物质的化学状态和局部成分，(Ii)通过最先进的X射线断层扫描和透射式X射线显微镜来确定纳米结构电极的晶内和晶间缺陷的生长和形态演变，(Iii)使用内部开发的环境纳米压痕来确定氧化物阴极的结构和机械降解对电荷状态、充电方案和循环历史的依赖，以及(Iv)通过机器学习和对实验输出库的数据分析来识别成分-化学-形态相关性。这项研究描绘了电化学力学的概念上的激进光谱，并为开发具有弹性电化学和机械性能的陶瓷氧化物奠定了科学基础。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: Rechargeable batteries are key to electric automobiles and the integration of renewable energy. Mechanical degradation of the ceramic electrodes is an issue that causes capacity fade of the battery materials. Despite the steady progress in the battery technology, the understanding of mechanical aging and failure mechanisms lags behind, mostly due to the intrinsic complexity of electroceramic chemistry, structural/compositional heterogeneity, and sensitivity on the environment and operation conditions. This project seeks to elucidate the aging mechanisms of ceramic battery materials. The research creates fundamental knowledge on the material science of batteries via a close integration of novel experimental and modeling approaches. On the education front, the multifaceted collaboration between Purdue University, Virginia Tech, and SLAC National Accelerator Laboratory provides unique training opportunities for the students in this project. Efforts will continue to encourage underrepresented graduate and undergraduate students to join the project. Outreach efforts in collaboration with the Women in Engineering Program at Purdue University and Destination Areas at Virginia Tech will continue to promote the participation of women in science and engineering.TECHNICAL DETAILS: The overarching goal of this project is to understand the defect inception, accumulation, and growth at the interface or within the grains, and the inter-relationship of defect-microstructure-performance of Li-ion batteries using the operando synchrotron X-ray analytical techniques, environmental nanoindentation, and data mining. The research effort includes (i) characterizing the local redox reactions, chemical states of matter, and local composition over multiple length scales using synchrotron X-ray analytical techniques, (ii) determining the intragranular and intergranular defect growth and morphological evolution of the nanostructured electrodes by state-of-the-art X-ray tomography and transmission X-ray microscopy, (iii) identifying the dependence of the structural and mechanical degradation of oxide cathodes on the state of charge, charging protocol, and cycling history using in-house-developed environmental nanoindentation, and (iv) identifying the composition-chemistry-morphology correlation through machine learning and data analysis of the library of experimental output.. The research draws a conceptually radical spectrum of the electro-chemo-mechanics and establishes a scientific basis for developing ceramic oxides with resilient electrochemical and mechanical performance.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.