GOALI: Understanding and Resolving the Compositional and Structural Defects in High-Energy Lithium-Ion Battery Cathodes

随着可再生能源需求的增加，其生产、运输和储存必须是环境友好和可持续的。锂离子电池（LIB）由于其高能量密度而被广泛用于电动汽车和可再生电网。然而，由于性能下降，LIB在使用几年后达到其寿命。从经济的角度来看，所用电池金属的再利用（例如，锂、钴、镍）可以显著降低它们的成本，因为大部分成本在阴极电极材料中（30-40%）。从环境角度来看，处置废旧电池产生的有机溶剂和金属废物需要处理和最终储存。为了经济和环境效益，期望回收、再利用和再制造LIB用于可持续的能量存储。通过与工业合作伙伴MeecoTech的密切合作，该GOALI奖项专注于基本理解和解决高能锂离子电池阴极在运行过程中的成分和结构缺陷以及再生过程的影响。这些知识可用于开发一种节能、非破坏性的工艺，以实现可持续的锂离子电池再利用工艺技术。该项目还将通过提供设施、工具、实例、动手实验室经验和工业实习，整合研究生、本科生和大学预科教育和培训。该项目的主要目标是系统地了解各种高能阴极材料在电池运行过程中的成分和结构缺陷的形成机制，以及它们在非破坏性再生过程中的演变。为了实现这一目标，该项目的具体目标包括：（1）使用模型阴极材料表征LIB循环期间的成分和结构形成;（2）表征和理解非破坏性再生期间降解的LIB阴极的成分和结构演变;以及（3）基于高效的非破坏性方法制造新电池并充分表征再生电极活性颗粒的电化学性质。这些结果将为研究它们的组成/结构缺陷与氧化还原性能和稳定性之间的关系提供基础知识。这些知识不仅可以作为基础，进一步开发一种通用技术，以实现环境友好、低成本，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。

With the increased demand of renewable energy, its production, transportation and storage must be environmentally benign and sustainable. Lithium-ion batteries (LIBs) have been widely used in electric vehicles and renewable electricity grids due to their high energy density. However, LIBs reach their lifetime after a few years of service due to performance degradation. From an economic point of view, reuse of the battery metals used (e.g., lithium, cobalt, nickel) can significantly reduce their cost because a large portion of the cost is in the cathode electrode material (30-40%). From an environmental point of view, the organic solvent and metal wastes generated from disposal of used batteries require treatment and final storage. For economic and environmental benefits, it is desired to recycle, reuse and re-manufacture LIBs for sustainable energy storage. Through a close collaboration with the industrial partner MeecoTech, this GOALI award focuses on fundamental understanding and resolving the compositional and structural defects in high energy LIB cathodes during operation and the impacts of regeneration processes. Such knowledge can be used to develop an energy-efficient, non-destructive process towards a sustainable LIB re-use process technology. This project will also integrate graduate, undergraduate and pre-college education and training by providing facilities, tools, practical examples, hands-on laboratory experiences and industrial internships. A strong engagement in enhancing STEM diversity will also be made through broad-based outreach activities in the San Diego area.The primary goal of this project is to establish a systematic understanding of the formation mechanisms of the compositional and structural defects in a variety of high-energy cathode materials during cell operation, as well as understanding of their evolution during non-destructive regeneration processes. Towards this goal, the specific objectives of the project include: (1) to characterize the compositional and structural formations during LIB cycling using model cathode materials; (2) to characterize and understand the compositional and structural evolution of degraded LIB cathodes during non-destructive regeneration; and (3) to fabricate new cells and fully characterize the electrochemical properties of regenerated electrode active particles based on the efficient non-destructive method. The results will provide fundamental knowledge of the correlation between their composition/structure defects and redox properties and stability. Such knowledge can not only be applied as the basis to further develop a general technology to allow an environmental benign, low-cost, and robust non-destructive strategy for effective regeneration of used LIB but also provide guidelines for better design of LIB active particles.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.