Solvothermal strategy for direct regeneration of high-performance cathode materials from spent lithium-ion battery

Abstract

Direct regeneration of cathode materials from spent lithium-ion batteries is efficient but suffers from the difficulty of accurately replenishing lithium, leading to poor performance of the regenerated materials. In this research, a solvothermal strategy for direct regeneration of spent cathode material into high electrochemical performances cathode material is reported. Spent LiNi0.5Co0.2Mn0.3O2 is directly regenerated by combining CH3CH2OH-LiNO3 solvothermal relithiation and thermal annealing step. The results indicate that lithium can be precisely replenished to the missing sites, and the regenerated materials return to a stable layered structure, corresponding to excellent cyclability (90.23 % capacity retention after 560 cycles at 1 C). Owing to solvent circulation and the low relithiation temperature, the regeneration process displays low energy consumption, low CO2 emissions and high profit; thus, presenting a promising route for direct regeneration of high-performance cathode materials from spent lithium-ion batteries.