With the widespread application of lithium-ion batteries,the spent lithium-ion batteries are increasing year by year,and their recycling and reuse are urgent.At present,the recovery of LiFePO4 cathode materials from spent lithium-ion batteries mainly focuses on the extraction and recovery of the high-value lithium,while there is little research on the recovery and utilization of the remaining low-value lithium extraction slag.The H3PO4-H2SO4 mixed acid leaching method was used to recover the iron phosphate from the lithium extraction slag,and its high-value utilization pathway was ex-plored.Under the optimal conditions,the leaching rate of iron phosphate from the lithium extraction slag reaches 99.69%,the crystallization yield reaches 97.14%,and the comprehensive recovery rate reaches 96.83%.The regenerated iron phosphate meets the battery grade iron phosphate standard.The lithium iron phosphate cathode material prepared with the obtained iron phosphate exhibits good electrochemical performance.The specific discharge capacities of the synthesized lithium iron phosphate reach 155.1 and 129.0 mAh/g at 0.1 C and 5 C,respectively.The capacity retention is 98.4%after 300 cycles at 5 C.This work provides a feasible approach for large-scale recovery and uti-lization of the lithium extraction slag.
关键词
废旧锂离子电池/磷酸铁锂/提锂渣/回收
Key words
spent lithium ion batteries/lithium iron phosphate/lithium extraction slag/recycling
维普
万方数据