A novel and practical hydrothermal method for synthesizing LiNi1/3Co1/3Mn1/3O2 cathode material

Abstract: The cathode material, LiNi1/3Co1/3Mn1/3O2, has attracted significant attention for lithium-ion batteries owing to its high stability and high capacity retention; however, its capacity and rate performance need further improvement. This study proposes a novel and practical hydrothermal method for synthesizing LiNi1/3Co1/3Mn1/3O2 with low agglomeration and better electrochemical performance. Herein, commercial precursor Ni1/3Co1/3Mn1/3(OH)2, and stoichiometric amount of LiOH·H2O were used as starting materials. The proposed method includes a hydrothermal process without solid-liquid separation and a short heat treatment. The optimal hydrothermal conditions were explored. The hydrothermal prepared cathode material exhibited better electrochemical performance than that prepared by the traditional calcination method. Less agglomeration was observed using scanning electron microscope and higher Li+ diffusion coefficient was detected by cyclic voltammetry tests. The crystal structure refinement results suggest that the hydrothermal prepared cathode material had a more stable crystal structure with a lower lattice distortion and lower Li/Ni cation mixing. These features can be attributed to the lithiation reaction in the hydrothermal process and short calcination time of the heat treatment. The proposed hydrothermal method is simple and practical, avoiding high lithium consumption and wastewater discharge.