电化学还原辅助废旧锂离子电池正极材料高效浸出

Electrochemical Reduction Assisted Efficient Leaching of Valuable Metals from Spent Lithium Ion Batteries

为了提高废旧锂离子电池正极材料中有价金属的浸出效率,采用电化学还原法实现对正极材料中有价金属的高效浸出。采用单因素试验探索硫酸浓度、浸出时间、温度和电流密度等因素对锂、镍、钴和锰浸出率的影响,借助扫描电镜、X射线衍射仪对电化学浸出前后正极片的表面形貌、元素分布及物相组成进行综合分析。结果表明:在外加电场的作用下实现了有价金属的还原,正极材料浸出后,主要剩余具有多孔结构的黏结剂PVDF;在硫酸浓度0.8 mol/L、浸出时间60 min、温度50℃、电流密度30 mA/cm^(2)的条件下,锂、镍、钴和锰的浸出率可分别达到97.2%、95.68%、95.09%、94.61%。

In order to promote leaching of valuable metals from cathode material in spent lithium ion batteries(LIBs),the effective leaching of valuable metals from cathode materials of spent LIBs was realized by electrochemical reduction method.Effects of concentration of sulfuric acid,leaching time,temperature,and current density on leaching efficiency of lithium,nickel,cobalt,and manganese was explored by single-factor experiment.The surface morphology,element distribution and phase composition of cathode materials before and after electrochemical leaching were analyzed by means of SEM and XRD.The results show that valuable metals are reduced assisted by electric field,the binder PVDF with a porous structure is mainly left after leaching of cathode material.The leaching efficiency of lithium,nickel,cobalt and manganese is 97.2%,95.68%,95.09%and 94.61%,respectively under the conditions including concentration of sulfuric acid of 0.8 mol/L,leaching time of 60 min,temperature of 50℃,and current density of 30 mA/cm^(2).