Synthesis of high-nickel and high-performance ternary cathode materials through spent lithium-ion batteries recycling system

In order to minimize the effect of energy consumption and environment risk, the ternary nickel-cobalt-manganese metals from existing spent lithium-ion batteries (LIBs) recycling system need for higher value-added utilization, such as synthesis for commercial high-nickel cathode materials. In this study, the nickel-cobalt-manganese mixed solution obtained from spent LIBs recycling system was used as raw material for the synthesis. After secondary precipitation, the precursors with different nickel contents were synthesized by the same equipment, and the cathode material was synthesized by calcination. This method has good adaptability for different nickel contents in the same equipment. The optimized conditions are listed as follows: (2 M mixed salt solution, 5 M NaOH, 15 wt% NH3·H2O, 65 °C, 1000 rpm speed, and 24 h aging time). The stable crystal forms of LiNixCoyMn(1-x-y)O2(NCM) (x = 0.50, 0.55, 0.60 and 0.80) with an average particle size of 5 μm was synthesized after secondary precipitation, thus the cation mixing degree reduced and the tap density increased. The electrochemical characterization of the four materials shows that the first discharge specific capacity of NCM811, NCM622, NCM551530 and NCM523 are 203.0 mAh/g, 188.5 mAh/g, 188.3 mAh/g, and 150.5 mAh/g at 0.1 C, respectively. Moreover, the capacity retention rate of NCM523 is 100.0% after 100 cycles at 1 C under high temperature of 50 °C.