废旧磷酸铁锂材料的固相再生及电化学性能研究  

Regeneration of spent LiFePO_4 cathode materials using solid state method and electrochemical performance

作　　者：陈永珍[1,2,3] 黎华玲 宋文吉 冯自平[1,2,3] CHEN Yongzhen;LI Hualing;SONG Wenji;FENG Ziping(Guangzhou Institute of Energy Conversion,Chinese Academy of Sciences,Guangzhou510640,Guangdong,China;Key Laboratory of Renewable Energy,Chinese Academy of Sciences,Guangzhou510640,Guangdong,China;Guangdong Provincial Key Laboratory of New and Renewable Energy Research and Development,Guangzhou510640,Guangdong,China)

机构地区：[1]中国科学院广州能源研究所,广东广州510640 [2]中国科学院可再生能源重点实验室,广东广州510640 [3]广东省新能源和可再生能源研究开发与应用重点实验室,广东广州510640

出　　处：《化工学报》2018年第12期5316-5325,共10页CIESC Journal

基　　金：广东省科技计划项目(2015B050501008);广东省新能源和可再生能源研究开发与应用重点实验室项目(y807ji1001)~~

摘　　要：热处理废旧电池正极片除去黏结剂后得到回收材料,在对回收材料元素定量分析的基础上,通过添加不同比例的Li、Fe、P源进行高温固相再生反应获得再生材料,研究杂质对再生材料的影响并优化再生反应原料比例。实验结果表明,再生反应过程中生成了Fe_2P杂质,该杂质衍射特征峰随着添加的Li、Fe、P源比例增加逐渐减弱;过多Li、Fe、P源添加时,导致再生材料结构致密性严重,Fe_2P杂质存在及材料结构过于致密,均降低了再生材料的容量性能。回收材料、化学计量比再生材料、过量元素源(1:1)再生材料首次放电容量分别为103.4、115.8和134.0 mA·h·g^(-1),再生反应后分别提高了11.99%、29.59%。上述三种材料50次循环后放电容量分别为100.9、108.0和115.3 mA·h·g^(-1)。The recycled cathode material was obtained after removing the binder of the scrap electrode by heat treatment.The regenerated materials were obtained by high temperature solid state method that adding different proportions of Li,Fe,and P element sources to the recycled material on the basis of quantitative analysis.In this paper,the influence of impurities on regenerated materials was investigated and the optimal proportion of regenerative reaction materials was obtained.The results showed that the Fe2P impurity occurred during the regeneration process.The diffraction characteristic peak of the Fe2P phase gradually declined with the increase of Li,Fe and P element sources.The presence of Fe2P phase decreases the specific capacity of the sample due to the low content of LiFePO4active material.The morphology of regenerated materials tends to become densification as the proportion of Li,Fe and P element sources increases.The fine and close microstructure decreases the capacity and cycle performance of regenerated materials.The initial specific discharge capacities of the recycled material,stoichiometric regenerated material and excess element sources regenerated material were103.4,115.8and134.0mA·h·g^-1,respectively.Compared with that of the recycled material,the initial specific discharge capacity of the two regenerated materials was improved by11.99%and29.59%,respectively.The discharge capacities of the above three materials after50cycles are100.9,108.0and115.3mA·h·g^-1.

关 键 词：废旧电池 磷酸铁锂 元素补充 回收 再生 电化学 

分 类 号：TM912.9[电气工程—电力电子与电力传动]