Al在废旧及修复LiFePO4/C中的存在形式  

Effect of Al on the Performance of Repairing LiFePO4/C Material

作　　者：李荐[1,2,4] 张敏超 王利华 赵小勇 李花 肖宜华 池哲曦 田基德 申昆 LI Jian;ZHANG Min-chao;WANG Li-hua;ZHAO Xiao-yong;LI Hua;XIAO Yi-hua;CHI Zhe-xi;TIAN Ji-de;SHEN Kun(School of Materials Science and Engineering,Central South Universiy,Changsha 410083,China;Beijing Sai De Mei Resources Recyeling Research Institute Co.,Ltd.,Bejing 100000 China;School of Meallurgy and Enironment,Central South Unirersity,Changsha 410083,China;Hunan Zhengyuan Institute for Energy Storage Materials and Derices,Changsha 410083,China)

机构地区：[1]中南大学材料科学与工程学院,湖南长沙410083 [2]北京赛德美资源再利用研究院有限公司,北京100000 [3]中南大学冶金与环境学院,湖南长沙410083 [4]湖南省正源储能材料与器件研究所,湖南长沙410083

出　　处：《湖南有色金属》2020年第6期42-48,共7页Hunan Nonferrous Metals

基　　金：广州市科学研究计划项目“废旧动力电池梯次利用及无害化回收关键技术研究”(专201804020024)。

摘　　要：锂电池正极材料回收方法中,物理修复相对于湿法冶金回收法具有工艺流程短、环保处理成本低、经济附加值高等优点。但在机械粉碎正极极片获得正极材料的过程中不可避免地会引入Al杂质,影响回收再生材料的物化性能,文章旨在研究Al杂质在物理法修复材料中的存在形式及其影响。文章首先研究杂质Al对商用LiFePO4/C电化学性能的影响,然后通过焙烧修复过程前后表征结果的对比,揭示了Al在回收及修复材料中的分布规律与存在形式。电化学性能测试表明,商用LiFePO4/C材料中Al含量越高,电池的放电比容量越低、倍率和循环性能越差,但对其自放电基本无影响。对含Al的废旧LiFePO4/C材料进行修复,采用XPS、SEM、Mapping研究发现,Al均匀分布在Fe和P的周围,回收和修复的LiFePO4/C材料中均有Al3+,其存在形式稳定。In the recovery method of LiFePO4/C battery,physical repair method has the advantages of short process and high economical value comparing to hydrometallurgical recovery method.However,it is inevitable to lead some impurity Al from the aluminum foil in the process of mechanical crushing.This paper focuses on the effect of impurity Al on the performance of LiFePO4/C battery and the existence of Al in spent material.Electrochemical tests show that,the higher the Al content of commercial LiFePO4/C materials,the lower the discharge specific capacity,the worse the rate and cycle performance.However,it has no effect on its self-discharge effect.In virtue of X photoelectron spectroscopy(XPS)and scanning electron microscopy(SEM)studies,it can been seen that Al elements evenly distributed around Fe and P.Al3+ in the spent and regenerated LiFePO4/C materials is stable.The Al3+ may form a new substance or take the position of other elements in the crystal to cause lattice distortion.

关 键 词：锂离子电池 废旧LiFePO4/C材料 物理法修复 杂质 电化学性能 

分 类 号：TG111.1[金属学及工艺—物理冶金]