A novel acid-free leaching route of recovering Li2CO3 and FePO4 from spent LiFePO4 black powder.

With the rapid increase in the usage of lithium ion batteries, recovering Li 2 CO 3 from LiFePO 4 black powder has become an issue of public concern. Nowadays, the widely used acid leaching technology has some obvious disadvantages, such as complex recovery process, serious equipment corrosion and unavoidable secondary pollution. In this work, a novel acid-free leaching route of recovering Li 2 CO 3 and FePO 4 from LiFePO 4 black powder is proposed. This novel route does not include inorganic or organic acid leaching, complex pH adjustment and wastewater treatment processes. After optimizing the technological conditions, Li 2 CO 3 and FePO 4 with high purity are recovered with high recovery rate of over 96%. Then, the recovered Li 2 CO 3 and FePO 4 are used as iron and lithium sources to regenerate LiFePO 4 and the electrochemical performances are compared in detail. When the molar ratio of Li 2 CO 3 :FePO 4 :C 6 H 12 O 6 (glucose) is 1.03:2:0.35, the regenerated LiFePO 4 (R-LFP-0.35) cathode displays the optimal electrochemical performance with the discharge capacity of 163.9 mAh g−1 at 0.1 C, 120 mAh g−1 at 4 C and excellent capacity retention ratio of 98.0% after 100 cycles at 0.2 C. This work provides a new green and environmentally friendly strategy for the recycling of LiFePO 4 black powder. • A novel acid-free leaching route of recovering Li 2 CO 3 and FePO 4 is proposed. • The closed-loop recycling route improves the recovery rate of Li 2 CO 3. • The recovered Li 2 CO 3 and FePO 4 are of high purity. • The regenerated LiFePO 4 cathode displays excellent electrochemical properties. [ABSTRACT FROM AUTHOR]