Synthesis and electrochemical performance of cathode material Li _1.2Co_0.13Ni_0.13Mn_0.54O₂ from spent lithium-ion batteries

Li-rich layered oxide Li_1.2Co_0.13Ni _0.13Mn_0.54O₂ has been successfully re-synthesized using the ascorbic acid leaching solution of spent lithium-ion batteries as the raw materials. A combination of oxalic acid co-precipitation, hydrothermal and calcination processes was applied to synthesize this material. For comparison, a fresh sample with the same composition has been also synthesized from the commercial raw materials using the same method. X-ray diffraction (XRD), scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS) and electrochemical measurements are carried out to characterize these samples. XRD results indicate that both samples have the layered α-NaFeO₂ structures with a space group of R3̄m. No other crystalline phase was detected by XRD. The electrochemical results show that the re-synthesized and fresh-synthesized sample can deliver discharge capacities as high as 258.8 and 264.2 mAh g^-1 at the first cycle, respectively. After 50 cycles, discharge capacities of 225.1 and 228 mAh g ^-1 can be obtained with capacity retention of 87.0 and 86.3%, respectively. This study suggests that the leaching solution from spent lithium ion batteries can be recycled to synthesize Li-rich cathode materials with good electrochemical performance.