LI Jiahao1, WEI Neng1, LI Jinlong1, Sabereh Nazari1, HE Yaqun1,2
（1.School of Chemical Engineering and Technology, China University of Mining and Technology, Xuzhou 221116, China;2. Hengchuang Ruineng Environmental Protection Technology Co., Ltd., Huizhou 516200, China）
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
中图分类号：TD982 文献标志码：A
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。
文章编号：1008-5548（2022）06-0091-08
DOI:10.13732/j.issn.1008-5548.2022.06.012
