储能科学与技术 ›› 2022, Vol. 11 ›› Issue (1): 45-52.doi: 10.19799/j.cnki.2095-4239.2021.0388

• 储能材料与器件 • 上一篇    下一篇

废磷酸铁锂正极材料资源化回收工艺

王子璇1(), 李俊成1(), 李金东1, 易娟2, 石霖2, 吴旭1()   

  1. 1.华中科技大学环境科学与工程学院,湖北 武汉 430074
    2.湖北华德莱节能减排科技有限公司,湖北 武汉 430070
  • 收稿日期:2021-08-02 修回日期:2021-08-09 出版日期:2022-01-05 发布日期:2022-01-10
  • 通讯作者: 吴旭 E-mail:m202073929@hust.edu.cn;profxuwu@hust.edu.cn
  • 作者简介:王子璇(1997—),女,硕士研究生,研究方向为废旧锂离子电池处理与资源化,E-mail:m202073929@hust.edu.cn;共同第一作者:李俊成(1997—),男,硕士研究生,研究方向为固体废物处理与资源化,E-mail:juncheng87@foxmail.com|王子璇(1997—),女,硕士研究生,研究方向为废旧锂离子电池处理与资源化,E-mail:m202073929@hust.edu.cn;共同第一作者:李俊成(1997—),男,硕士研究生,研究方向为固体废物处理与资源化,E-mail:juncheng87@foxmail.com|吴旭,博士,教授,研究方向为电化学环境工程,E-mail:profxuwu@hust.edu.cn
  • 基金资助:
    国家“千人计划”青年人才项目

Resource recovery technology of spent lithium iron phosphate cathode material

Zixuan WANG1(), Juncheng LI1(), Jindong LI1, Juan YI2, Lin SHI2, Xu WU1()   

  1. 1.School of Environmental Science and Engineering, Huazhong University of Science and Technology, Wuhan 430074, Hubei, China
    2.Hubei Hua Delai Energy Saving and Emission Reduction Technology Co. Ltd. , Wuhan 430070, Hubei, China
  • Received:2021-08-02 Revised:2021-08-09 Online:2022-01-05 Published:2022-01-10
  • Contact: Xu WU E-mail:m202073929@hust.edu.cn;profxuwu@hust.edu.cn

摘要:

废磷酸铁锂电池的回收处理是目前的行业焦点。针对废磷酸铁锂电池回收工艺过程复杂、二次废料过多、成本高等问题,提出了一条基于固相电解技术的电化学法回收工艺路线,降低了次生污染的风险,实现了废磷酸铁锂电池高产率低成本回收。工艺采用磷酸体系电解和分步沉淀的方法,制备二水合磷酸铁和磷酸锂。开展了电解过程中的参数优化和沉淀分离的因素研究,重点分析了电解电压、磷酸电解液浓度及电解前浸泡时间等参数对铁、锂浸出率的影响规律。研究结果表明,电解电压为2.5 V,磷酸电解液浓度为0.6 mol/L,先浸泡60 min后电解30 min处理过后,锂离子浸出率为95.6%,铁离子浸出率为91.3%。通过氨水控制溶液pH分步沉淀二水合磷酸铁和磷酸锂,二水合磷酸铁的回收率可达98.8%,锂离子的回收率可达99.4%。

关键词: 废磷酸铁锂, 固相电解, 磷酸电解液, 分步沉淀

Abstract:

Spent lithium iron phosphate (SLFP) batteries recycling is increasingly being researched. In this study, an electrochemical recycling method for SLFP is proposed based on solid-phase electrolysis; in reference to that, the technology exhibits complex procedures, extra secondary wastes, and high cost, resulting in reduced risk of secondary pollution and improved yield, and lower price. Phosphoric acid electrolysis system and stepwise precipitation method were adopted to prepare FePO4·2H2O and Li3PO4. The study covers parameter optimization in the electrolysis process and factor analysis for the precipitation separation. It analyzes the effect of parameters such as cell voltage, H3PO4 electrolyte concentration, and soaking time before electrolysis on Fe and Li leaching rates. After 60 min of soaking, with 30 min electrolysis in 0.6 mol/L H3PO4 electrolyte at 2.5 V, the Fe and Li leaching rates were 91.3% and 95.6%, respectively. The solution pH was controlled by stepwise addition of ammonia water to precipitate FePO4·2H2O and Li3PO4, of which a corresponding 98.8% and 99.4% recovery rates were achieved. respectively.

Key words: spent lithium iron phosphate, solid phase electrolysis, phosphoric acid electrolyte, step precipitation

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