废旧磷酸铁锂正极材料的高价值回收利用  

High-value recycling of spent lithium iron phosphate cathode materials

作　　者：赵来安 ZHAO Laian(Xiamen Tungsten New Energy Materials Co.,Ltd.,Xiamen 361026,Fujian,China)

机构地区：[1]厦门厦钨新能源材料股份有限公司,福建,厦门361026

出　　处：《有色金属科学与工程》2025年第2期264-271,共8页Nonferrous Metals Science and Engineering

摘　　要：文中介绍了一种对废旧磷酸铁锂正极材料进行高价值回收利用的方法。材料中的Fe、P、Li元素分别以FeSO_(4)、FePO_(4)和Li_(3)PO_(4)形式回收,以Li_(3)PO_(4)形式回收Li的回收率达到93%。该回收工艺不使用磷酸或磷酸盐,具体包括5个步骤:(1)将废旧磷酸铁锂正极材料用硫酸酸溶;(2)将1/3以上的Fe^(2+)离子以FeSO_(4)形式重结晶出来;(3)对Fe^(2+)进行氧化处理并调整溶液pH至2.0~3.0,使Fe^(2+)离子以FePO_(4)形式析出,制得的FePO_(4)可以用于固相法制备LiFePO_(4);(4)将分离FePO_(4)后滤液的pH调至11.0,其中的Li^(+)、PO_(4)^(3-)离子浓度达到沉淀析出条件,析出Li_(3)PO_(4)沉淀;(5)将制得的亚铁盐与Li_(3)PO_(4)通过水热法制备LiFePO_(4),制得的LiFePO_(4)材料表现出良好的电化学性能。A high-value recycling method was introduced for spent lithium iron phosphate (LFP) cathode materials.Fe,P,and Li elements were recovered in the forms of FeSO_(4),FePO_(4),and Li_(3)PO_(4),respectively.The recycling yield of Li recovered in the form of Li_(3)PO_(4) reached 93%.The recycling process was free of phosphoric acid and phosphate and involved five steps:(1) dissolving the waste lithium iron phosphate cathode material with sulfuric acid;(2) recrystallizing more than one-third of Fe^(2+)ions as FeSO_(4);(3) oxidizing the remaining Fe^(2+)ions and adjusting the pH value of the solution to 2.0~3.0 to precipitate Fe^(2+)ions of FePO_(4),which can be used for solidphase preparation of LiFePO_(4);(4) adjusting the pH value of the filtrate after separating FePO_(4) to 11.0,where the concentrations of Li~+ions and PO~3_(4)~-ions met the precipitation conditions to precipitate Li_(3)PO_(4);(5) using the obtained ferrous salt and Li_(3)PO_(4) to prepare LiFePO_(4) by hydrothermal methods,with the resulting LiFePO_(4exhibiting) good electrochemical performance.

关 键 词：废旧磷酸铁锂 回收 无磷酸工艺 硫酸亚铁 磷酸锂 

分 类 号：TM912[电气工程—电力电子与电力传动]