李家皓¹， 韦 能¹， 李金龙¹， Sabereh Nazari¹， 何亚群^1,2

（1. 中国矿业大学化工学院， 江苏徐州221116； 2. 恒创睿能环保科技有限公司， 广东惠州516200）

DOI：10.13732/j.issn.1008-5548.2022.06.012

收稿日期： 2022-06-04， 修回日期：2022-10-13，在线出版时间：2022-11-01。

基金项目： 广东省重点专项研发计划项目，编号：2020B090919003。

第一作者简介： 李家皓（1997—），男，硕士研究生，研究方向为矿业工程。E-mail： Ts21040077a31@cumt.edu.cn。

通信作者简介： 何亚群（1963—），男，教授，博士，博士生导师，研究方向为矿物加工工程。E-mail： yqhe@cumt.edu.cn。

摘要：为实现失效磷酸铁锂(LiFePO₄)电池正极材料的回收和再利用，采用仪器分析和表征方法，研究LiFePO₄正极材料失效前、后的理化性质。结果表明：失效后LiFePO₄电池正极材料中含有大量的Fe、 P、 Ni,少量的Cu、 Co和微量的F元素，晶相结构未发生明显改变，Fe主要以Fe²⁺和Fe³⁺形式存在；LiFePO₄电池正极片失效后表面呈现不规则的波浪状缺陷和坑状凹陷；在失效过程中，LiFePO₄正极材料颗粒表面产生裂纹，破碎后形成的小颗粒变得黏连、杂乱和团聚，降低正极材料的电化学性能；失效后颗粒表面出现的约20 nm厚的PVDF膜结构影响颗粒表面的疏水性，降低浮选效率。

关键词：磷酸铁锂电池；正极材料；失效电池；理化性质

Abstract：In order to recover and reuse the cathode material of lithium iron phosphate(LiFePO₄) battery, physicochemical properties of LiFePO₄ cathode material before and after failure were studied by instrumental analysis and characterization methods. The results show that the cathode material of LiFePO₄ battery contains a large amount of Fe, P and Ni, a small amount of Cu and Co, and trace of F. The crystal structure of cathode material does not change significantly, and Fe mainly exists in the form of Fe²⁺ and Fe³⁺. Irregular wavy defects and pit-like depressions appear on the surface of cathode plate of failed LiFePO₄ battery. During the failure process, cracks occur on the surface of LiFePO₄ cathode material particles, and the small particles formed after crushing become adhesive, disorderly and agglomerate, which reduce the electrochemical performance of the cathode material. After the failure, the PVDF membrane with a thickness of about 20 nm appears on the particle surface, which affect the hydrophobicity of the particle surface and reduce the flotation efficiency.

Keywords：lithium iron phosphate battery; cathode material; failed battery; physicochemical properties

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