Micron-Sized Monodisperse Particle LiNi_0.6Co_0.2Mn_0.2O₂ Derived by Oxalate Solvothermal Process Combined with Calcination as Cathode Material for Lithium-Ion Batteries

Ni-rich cathode LiNi_xCo_yMn_1-x-yO₂ (NCM, x ≥ 0.5) materials are promising cathodes for lithium-ion batteries due to their high energy density and low cost. However, several issues, such as their complex preparation and electrochemical instability have hindered their commercial application. Herein, a simple solvothermal method combined with calcination was employed to synthesize LiNi_0.6Co_0.2Mn_0.2O₂ with micron-sized monodisperse particles, and the influence of the sintering temperature on the structures, morphologies, and electrochemical properties was investigated. The material sintered at 800 °C formed micron-sized particles with monodisperse characteristics, and a well-order layered structure. When charged-discharged in the voltage range of 2.8-4.3 V, it delivered an initial discharge capacity of 175.5 mAh g^-1 with a Coulombic efficiency of 80.3% at 0.1 C, and a superior discharge capacity of 135.4 mAh g^-1 with a capacity retention of 84.4% after 100 cycles at 1 C. The reliable electrochemical performance is probably attributable to the micron-sized monodisperse particles, which ensured stable crystal structure and fewer side reactions. This work is expected to provide a facile approach to preparing monodisperse particles of different scales, and improve the performance of Ni-rich NCM or other cathode materials for lithium-ion batteries.