储能科学与技术 ›› 2022, Vol. 11 ›› Issue (7): 2066-2074.doi: 10.19799/j.cnki.2095-4239.2021.0674

• 储能材料与器件 • 上一篇    下一篇

废旧磷酸铁锂电池电极材料的硫酸化焙烧-水浸新工艺

张肖洒(), 王宏源, 李振彪, 夏志美()   

  1. 湖南工业大学材料与先进制造学院,湖南 株洲 412007
  • 收稿日期:2021-12-01 修回日期:2022-01-04 出版日期:2022-07-05 发布日期:2022-06-29
  • 通讯作者: 夏志美 E-mail:1694190694@qq.com;zhimei_x@163.com
  • 作者简介:张肖洒(1994—),女,硕士研究生,研究方向为资源回收与环保,E-mail:1694190694@qq.com
  • 基金资助:
    湖南工业大学研究生科研创新项目(CX2032);国家自然科学基金项目(51704107);湖南省自然科学基金项目(2018JJ3124);湖南省高等学校重点实验室(湘教通[2019]379);矿物材料及其应用湖南省重点实验室开放课题(MMA201705)

New process of sulfated roasting-water leaching for treating electrode material of spent lithium iron phosphate batteries

Xiaosa ZHANG(), Hongyuan WANG, Zhenbiao LI, Zhimei XIA()   

  1. College of Materials and Advanced Manufacturing, Hunan University of Technology, Zhuzhou 412007, Hunan, China
  • Received:2021-12-01 Revised:2022-01-04 Online:2022-07-05 Published:2022-06-29
  • Contact: Zhimei XIA E-mail:1694190694@qq.com;zhimei_x@163.com

摘要:

针对目前急需解决的废旧磷酸铁锂(LiFePO4)电池中有价金属的清洁高效提取问题,提出硫酸化焙烧脱氟-水浸新工艺。用TG-DSC和XRD表征确定了正负极片热处理的适宜条件为:空气气氛、温度575 ℃。采用正交实验和单因素实验研究了浓硫酸使用量、焙烧时间和温度。水浸液固比、温度及时间对正负极混合料粉末中Fe、P和Li元素浸出率和浸出液中F元素残存率的影响。确定了最优焙烧工艺条件为:浓硫酸使用量为理论用量的0.75倍、焙烧时间2.5 h、温度110 ℃;最优水浸工艺条件为:液固比4∶1(mL/g)、温度60 ℃、时间2 h。在此工艺条件下,P和Li的浸出率都达到100%,Fe元素的浸出率为98.85%,F元素在浸出液中的残存率仅为13.11%。

关键词: 废旧磷酸铁锂电池, 电极材料, 硫酸化焙烧, 水浸, 浸出率

Abstract:

This study proposes a novel sulfated roasting defluorination and water leaching technique to recover precious metals from wasted lithium iron phosphate (LiFePO4) batteries cleanly and efficiently. The air atmosphere and temperature of 575 ℃ were determined as the appropriate thermal decomposition conditions of binder by TG-DSC and XRD. By using orthogonal and single-factor experiments, the effects of concentrated sulfuric acid dosage, roasting time and temperature, liquid-solid ratio, temperature, and time of water leaching on the leaching rate of Fe, P, and Li from spent lithium iron phosphate electrode mixture powder and the residual rate of F in the leaching solution were investigated. The optimal roasting process conditions were determined as follows: 0.75 times the theoretical amount of concentrated sulfuric acid, roasting time of 2.5 h, and roasting temperature of 110 ℃. The optimal water leaching process conditions were determined as follows: liquid-solid ratio of 4∶1, a temperature of 60 ℃, and time of 2 h. Under these conditions, both the leaching rates of P and Fe are up to 100%, the leaching rate of Fe is 98.85%, and the residual amount of F in the leaching solution is only 13.11%.

Key words: spent lithium iron phosphate batteries, electrode material, sulfated roasting, atmospheric water leaching, leaching rate

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