Enhancing the high-voltage electrochemical performance of the LiNi_0.5Co_0.2Mn_0.3O₂ cathode materials via hydrothermal lithiation

The chemical lithiated transition metal oxide precursor has been prepared via a hydrothermal process and successfully used for preparing the LiNi_0.5Co_0.2Mn_0.3O₂ cathode materials by the post-heat treatment. The results indicate that the lithiated transition metal oxide precursor inherits the morphology of the Ni_0.5Co_0.2Mn_0.3(OH)₂ precursor but has a typical #alpha#-NaFeO₂-type (space group: R-3 m) layered structure with an imperfect crystallinity, and the Li is homogenously distributed in the particles. It is further confirmed that the obtained LiNi_0.5Co_0.2Mn_0.3O₂ cathode material has a suppressed cation mixing resulting in an excellent electrochemical performance. It delivers the high initial capacity of 187.3 mAhg⁻¹ at 1 C over the high cutoff voltage range of 3.0–4.6 V and the excellent capacity retention of 81.90% after 100 cycles as well as the rate capability of 152.3 mAhg⁻¹ at 8 C, which are attributed to the low polarization, fast Li⁺ diffusion and small charge–discharge resistance of the as-prepared material upon cycling.