(1. 湘潭大学 化学学院 电化学能源储存与转换湖南省重点实验室，湘潭 411105
2. 湘潭大学 化学学院 新能源装备及储能材料与器件国家国际科技合作基地，湘潭 411105)
摘 要: 根据废旧LiFePO4正极片中各元素物理化学性质差异，通过高温焙烧、酸浸并选择不同沉淀剂分离等手段，回收废旧LiFePO4电池极片中Li、Fe元素和集流体-Al箔。Li首先以Li3PO4的形式回收，Fe以FePO4形式回收。结果表明：废旧LiFePO4电池极片经过600 ℃高温煅烧后，当溶解混合物的HCl浓度为5 mol/L时，在60 ℃加热搅拌4 h，混合粉料的溶解率达到了98%，未溶解的是残留的少量导电碳和PVDF。向滤液中加入3% SDS，调节滤液pH值至2，在80 ℃得到无定形FePO4可作为新制备LiFePO4的前驱体。继续向滤液中加入Na3PO4至饱和，可以最大程度地回收锂元素，Li以梭形形貌的Li3PO4形式沉淀。Fe的回收率为97%，Li的回收率可以达到96%。
关键字: 废旧LiFePO4电池；元素回收；原子经济；磷酸锂；磷酸铁
（1. Hunan Province Key Laboratory of Electrochemical Energy Storage and Conversion, School of Chemistry, Xiangtan University, Xiangtan 411105, China;
2. National Base for International Science and Technology Cooperation, School of Chemistry, Xiangtan University, Xiangtan 411105, China）
Abstract:According to the differences of the physical and chemical properties for each element in the spent LiFePO4 battery, Li, Fe and current collector-Al foil were atomic-economically recovered by high temperature sintering, acid leaching and adding different precipitating reagents. Lithium was first recovered in the form of Li3PO4, and iron was recovered in the form of FePO4. The results show that when the concentration of HCl is 5 mol/L, the dissolution rate of the mixed material reaches 98% when being heated at 60 ℃ for 4 h. The pH of the filtrate is adjusted to 2 after adding SDS to recover FePO4. Followed by adding of Na3PO4, when the concentration of Na3PO4 is close to saturation, lithium precipitates in the form of Li3PO4. The precipitation rate of iron can reach 97%, the precipitation rate of lithium can reach 96%.
Key words: spent LiFePO4 battery; element recycling; atomic economy; Li3PO4; FePO4
