Cation doping method for the restoration of spent LiNi1/3Co1/3Mn1/3O2 cathode material properties

Abstract

In recycling process of spent lithium-ion batteries (LIBs), the Al impurities are generally existed in the obtained spent cathode active material, which undoubtedly affect the physical and electrochemical features of the recovered active materials. In this study, the effects of different forms (Al and Al3 +) and gradient concentrations (0.2, 0.5, and 1 at%) of Al impurity were investigated in the recovery of spent LiNi1/3Co1/3Mn1/3O2 (NCM111) cathode. The Al3 + impurity can promote the nucleation and growth of primary particles and reduce the cation mixing in the NCM111 cathode material, which benefits to the improvement of electrochemical performance. The obtained regenerated NCM material (R-NCMA) cathode displayed a great capacity of 183.75 mAh/g at 0.5 C and good cycling stability after 200 cycles (a capacity of 85.91% maintained). Meanwhile, the existing Al impurity can produce the more additional internal side reactions on the surface of the electrode and further affect the electrochemical performance. Based on these results, the existing form and concentration of Al impurities should be further considered and well controlled in the recycling of spent LIBs.