废旧磷酸铁锂锂离子电池正极的回收  

Recycle of cathode in spent lithium iron phosphate Li-ion battery

作　　者：鲍维东 骆艳华 裴晓东[1,2] BAO Wei-dong;LUO Yan-hua;PEI Xiao-dong(Nanjing New Materials Research Institute Co.,Ltd.,Sinosteel,Nanjing,Jiangsu 211106,China;Anhui Tianyuan Technology Co.,Ltd.,Sinosteel,Maanshan,Anhui 243000,China)

机构地区：[1]中钢集团南京新材料研究院有限公司,江苏南京211106 [2]中钢集团安徽天源科技股份有限公司,安徽马鞍山243000

出　　处：《电池》2020年第2期200-203,共4页Battery Bimonthly

摘　　要：采用磷酸(H3PO4)溶液对废旧LiFePO4电池正极片在低温热解得到的粉末材料进行浸出,以铁盐溶液作为补充铁源,合成电池级磷酸铁(FePO4),并将滤液pH值调到8.0以上,得到工业级磷酸锂(Li3PO4)。通过SEM、XRD和电化学性能测试,研究热处理温度、反应原料配比与溶液pH值对回收产物形貌和性能的影响。将正极片在350℃下热解2 h分离得到的粉末加入到85℃的H3PO4溶液中,在n(P)∶n(Fe)为1.3∶1.0的条件下,制备的FePO4结晶度好。制备的电池在2.5~4.0 V充放电,0.2 C和2.0 C放电比容量最高分别达到160.2 mAh/g和150.3 mAh/g。以Li3PO4方式回收滤液中的锂元素,当p H值为10时,回收率达到90%,Li3PO4纯度在99.4%以上。Phosphoric acid(H3PO4) solution was used to leaching the powder obtained from the pyrolysis of spent lithium iron phosphate(LiFePO4) battery cathode plate at low temperature.Using iron salt solution as supplemental iron source,battery-grade iron phosphate(FePO4) was synthesized,and the p H of the filtrate was adjusted to above 8.0 to obtain industrial-grade lithium phosphate(Li3PO4).SEM,XRD and electrochemical performance tests were used to analyse the effects of heat treatment temperature,proportion of reaction raw materials and p H value of solutions on the morphology and performance of the recycled products.When the powders obtained form pyrolysis of the cathode plate at 350 ℃ for 2 h was added to the H3PO4 solution at85 ℃,n(P) ∶ n(Fe) was 1.3 ∶ 1.0,the crystallinity of the FePO4 was fine.The specific discharge capacities of LiFePO4 battery at 0.2 C and 2.0 C were reached 160.2 mAh/g and 150.3 mAh/g when charged-discharged in 2.5-4.0 V,respectively.When the pH value was 10,the lithium filtrate was recycled by Li3PO4,the lithium element recovery rate was 90.0%;the purity of Li3PO4 was above 99.4%.

关 键 词：锂离子电池 回收利用 热处理 磷酸铁(FePO4) 磷酸锂(Li3PO4) 

分 类 号：TM912.9[电气工程—电力电子与电力传动]