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

非技术描述：可充电电池是电动汽车和可再生能源集成的关键。陶瓷电极的机械退化是导致电池材料的容量衰减的问题。尽管电池技术取得了稳步进展，但对机械老化和失效机制的理解仍然滞后，主要是由于电子陶瓷化学的内在复杂性，结构/成分异质性以及对环境和操作条件的敏感性。本计画旨在探讨陶瓷电池材料之老化机制。该研究通过紧密结合新颖的实验和建模方法，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。与普渡大学的妇女参与工程项目和弗吉尼亚理工大学的目的地地区合作开展的外联工作将继续促进妇女参与科学和工程。这个项目的首要目标是了解界面或晶粒内的缺陷起始、积累和生长，利用同步辐射X射线分析技术、环境纳米压痕技术和数据挖掘技术，研究了锂离子电池缺陷-微观结构-性能之间的相互关系。研究工作包括（i）使用同步加速器X射线分析技术表征局部氧化还原反应、物质的化学状态和多个长度尺度上的局部组成，（ii）通过最先进的X射线断层扫描和透射X射线显微镜确定纳米结构电极的粒内和粒间缺陷生长和形态演变，（iii）使用内部开发的环境纳米压痕来识别氧化物阴极的结构和机械降解对充电状态、充电协议和循环历史的依赖性，以及（iv）通过机器学习和实验输出库的数据分析来识别组成-化学-形态学相关性。该研究绘制了电化学力学的概念激进光谱，并为开发具有弹性电化学和机械性能的陶瓷氧化物建立了科学基础。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: 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.