一步法回收锂离子电池三元正极材料及其性能影响

One-Step Recycling of Trinary Cathode Materials in Lithium Ion Batteries and the Impact on Their Performance

  • 摘要: 采用直接一步法回收废旧锂离子电池中的三元正极材料LiNi0.5Co0.2Mn0.3O2,将拆解得到的三元废料经分离、热解处理后进行酸浸,对酸浸溶液进行元素测定后补加Ni、Co、Mn源,使其物质的量之比符合n(Ni)∶n(Co)∶n(Mn)=5∶2∶3. 调整后的溶液直接与草酸钠溶液进行共沉淀,得到草酸盐前驱体,最后与锂源混合,烧结得到三元再生正极材料. 结果表明:再生正极材料的首次放电容量最高达162 mAh/g,充放电100次后的容量保持率接近88%. 但如果材料中杂质元素含量过高,则会对材料电化学性能造成负面影响. 该方法避免了传统方法中将金属元素逐一分离回收所造成的资源浪费和能源损耗,且制备得到的材料具有较高附加值,具有良好的商业化应用前景.

     

    Abstract: A direct one-step recycling process was developed to recycle the trinary materials from the spent lithium ion batteries. The spent materials were collected after battery disassembling, electrode separation and pyrolysis and subjected to acid leaching. The element concentration in the obtained solution from the leaching process was determined with elemental analysis, and proper Ni, Co and Mn sources were added into the solution, achieving a ratio of n(Ni)∶n(Co)∶n(Mn)=5∶2∶3. The adjusted solution was directly used to co-precipitated with sodium oxalate and the obtained oxalate precipitates were mixed with Li sources. The trinary materials were obtained after sintering. The results exhibited that the recycled materials with this method could release a discharge capacity of 162 mAh/g and had a capacity retention ratio of 88% after 100 cycles. However, high-content impurity would affect the material performance, resulting in inferior electrochemical properties. This novel method can avoid the resource waste and energy loss in the traditional recycling process, whereby every metal is separated. The obtained materials through this process have higher additional value, promising an attractive commercial prospect.

     

/

返回文章
返回