I2I Phase I: Optimization of selective lithium recovery from spent lithium iron phosphate batteries with a green and environmentally responsible process

I2I 第一阶段：采用绿色环保工艺优化从废磷酸铁锂电池中选择性回收锂

• 批准号: 566796-2021
• 负责人: Ghahreman, Ahmad
• 金额: $ 9.11万
• 依托单位: Queen's University
• 依托单位国家: 加拿大
• 项目类别: Idea to Innovation
• 财政年份: 2021
• 资助国家: 加拿大
• 起止时间: 2021-01-01 至 2022-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=728738
• 关键词: I2I; Phase; Optimization; selective; lithium

Lithium iron phosphate (LFP) batteries are among the lithium-ion batteries (LIBs) that have the lowest production cost among almost all lithium-ion batteries and have excellent performance. Unlike other types of LIBs, LFP battery manufacturing does not require any cobalt, nickel, or manganese, which are among the expensive ingredients of LIBs manufacturing. Therefore the manufacturing cost of these LFP batteries is significantly, often 50%, less than the other types of LIBs. The lower contained metal value within LFP batteries makes their recycling economically unattractive, particularly because the cost of reagents used in the recycling process exceeds the value of the metals (i.e. mostly lithium) recovered from the LFP batteries.This project further develops a process that has been designed to selectively leach lithium from shredded LFP batteries, while leaving behind iron and phosphorous. In other words, the process is designed to recover only the valuable metal, i.e. lithium, from the LFP batteries, thus minimizing the energy, water, and reagent costs of the process. The shredded LFP batteries are leached in a water-formic acid-hydrogen peroxide system, where the concentration of formic acid is designed to be around 1 M, and hydrogen peroxide is added as an oxidant in the range of 1 to 5 wt%. The lithium from the LFP batteries is then recovered into the leach solution as lithium formate. Subsequently, the lithium-rich solution is separated from the solid residues. The solution carries mostly lithium and an insignificant amount of iron as an impurity, often in the low mg/L Fe range. After a pH adjustment for iron removal, the process water is ready for crystallization of high-grade and high-quality lithium phosphate crystals, with a grade above 99.5% Li3PO4.The process is developed to use environmentally friendly reagents and is a closed-loop process, producing no wastewater; therefore, the process can be applied in the vicinity of cities, where spent batteries are available.

磷酸铁锂（LFP）电池是几乎所有锂离子电池中生产成本最低且性能优异的锂离子电池（LIB）之一。与其他类型的LIB不同，LFP电池制造不需要任何钴，镍或锰，这些都是LIB制造的昂贵成分。因此，这些LFP电池的制造成本比其他类型的LIB低得多，通常低50%。LFP电池中所含的金属价值较低，使得它们的回收在经济上没有吸引力，特别是因为回收过程中使用的试剂的成本超过了从LFP电池中回收的金属（即主要是锂）的价值。该项目进一步开发了一种工艺，该工艺旨在从切碎的LFP电池中选择性地浸出锂，同时留下铁和磷。换句话说，该方法被设计为仅从LFP电池中回收有价值的金属，即锂，从而使该方法的能量、水和试剂成本最小化。将切碎的LFP电池在水-甲酸-过氧化氢系统中浸出，其中甲酸的浓度被设计为约1 M，并且过氧化氢作为氧化剂以1至5wt%的范围添加。然后将来自LFP电池的锂作为甲酸锂回收到浸出溶液中。随后，将富锂溶液与固体残余物分离。该溶液主要携带锂和微量的铁作为杂质，通常在低mg/L Fe范围内。经过pH值调整除铁后，工艺水可用于结晶高品位和高质量的磷酸锂晶体，其品位超过99.5%Li3PO4。该工艺采用环保试剂，是一个闭环工艺，不产生废水;因此，该工艺可应用于城市附近，那里有废旧电池。