ERI: A Fundamental Investigation of the Effectiveness of Cathode Regeneration Process for Spent Lithium Ion Batteries

该奖项全部或部分由2021年美国救援计划法案（公法117-2）资助。随着运输和消费电子行业锂离子电池（LIB）的消耗量迅速增加，预计到2030年，需要处理或回收的废旧LIB数量将超过1100万公吨。然而，目前只有不到5%的废LIB被回收利用。因此，迫切需要开发一种环境友好且经济可行的LIB回收技术来管理危险但有价值的大量废LIB。该项目将系统地探索一种直接回收工艺，该工艺可能最大限度地提高报废锂离子电池的回报价值，旨在回收和再利用废旧锂离子电池中最有价值的阴极材料，用于新的锂离子电池制造。该项目的成果将促进直接阴极回收的发展，有助于最大限度地减少锂离子电池废物对环境的影响，确保未来电池原材料的供应，降低锂离子电池生产成本，并提高锂离子电池行业的可持续性。研究成果将通过学术期刊、会议、科学节和教育视频广泛传播，激发LIB回收技术的新思路，提高人们对LIB回收的经济和环境影响的理解。此外，不同教育水平的学生，特别是在STEM领域代表性不足的少数民族和妇女，将通过提供实践实验室经验进行培训。该项目的总体目标是从根本上了解直接回收不同退化程度的废阴极的有效性。考虑到在不同循环条件下产生寿命终止LIB的事实，预计废阴极将表现出各种程度的降解，包括锂损失、不可逆相变、晶间/晶内开裂、过渡金属溶解和表面层形成。为了模拟在各种降解条件下的废阴极以及它们如何通过直接再循环过程再生，合成、表征和再生不同类型的化学脱锂阴极。该项目旨在通过追求两个具体目标来实现其主要目标：（1）检查基于溶剂的分离处理期间化学脱锂阴极的化学，结构和电化学稳定性，以及（2）确定直接阴极再生用于再生不同降解程度的化学脱锂阴极的有效性。这项研究的结果将促进我们对直接阴极回收背后机制的理解，并加速该工艺的开发。从该项目中获得的新知识将为指导制定在不同健康状况下从废LIB中有效再生阴极材料的策略奠定坚实的基础。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而被认为值得支持。

This award is funded in whole or in part under the American Rescue Plan Act of 2021 (Public Law 117-2).As the consumption of lithium-ion batteries (LIBs) in the transportation and consumer electronic sectors rapidly increases, the volume of spent LIBs requiring disposal or recycling is expected to reach more than 11 million metric tons by 2030. However, less than 5% of spent LIBs are currently recycled. Thus, there is an urgent need to develop an environmentally friendly and economically viable LIB recycling technology to manage the hazardous, albeit valuable, large volumes of spent LIBs. This project will systematically explore a direct recycling process that could potentially maximize the return value from end-of-life LIBs, aiming to recover and reuse the most valuable cathode material in spent LIBs for new LIB manufacturing. The outcomes of the project will facilitate the development of direct cathode recycling that contributes to minimizing the environmental impacts of LIB wastes, securing the future supply of battery raw materials, lowering the cost of LIB production, and improving the sustainability of the LIB industry. The research results will be broadly disseminated through academic journals, conferences, science festivals, and educational videos, inspiring new ideas for LIB recycling technologies and improving people’s understanding of the economic and environmental impacts of LIB recycling. Furthermore, students of various education levels, especially underrepresented minorities and women in the STEM fields, will be trained by providing hands-on laboratory experiences. The overarching goal of this project is to establish a fundamental understanding of the effectiveness of direct recycling on spent cathodes at different degrees of degradation. Given the fact that end-of-life LIBs are generated under different cycling conditions, the spent cathodes are expected to exhibit various levels of degradation that involve lithium loss, irreversible phase transformation, inter/intragranular cracking, dissolution of transition metals, and surface layer formation. To simulate the spent cathodes at various degradation conditions and how they are regenerated by a direct recycling process, different types of chemically delithiated cathodes are synthesized, characterized, and regenerated. This project seeks to attain its primary goal by pursuing two specific aims: (1) to examine the chemical, structural, and electrochemical stabilities of chemically delithiated cathodes during solvent-based separation processing and (2) to determine the effectiveness of direct cathode regeneration for rejuvenating chemically delithiated cathodes at different degradation extents. The findings from this research will advance our understanding of the mechanisms behind direct cathode recycling and accelerate the process development. The new knowledge gained from this project will lay a solid foundation to guide the formulation of strategies for effectively regenerating cathode materials from spent LIBs at different state-of-health conditions.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.