Synthesis and characterization of LiNi0.5Co0.2Mn0.3O2 cathode material prepared by a novel hydrothermal process

Abstract A novel hydrothermal process followed by heat treatment was used for the preparation of the layered LiNi 0.5 Co 0.2 Mn 0.3 O 2 cathode materials for lithium ion batteries. The lithiated metal oxide precursor obtained from the hydrothermal process had a homogeneous distribution of metals and a weak crystallinity. The layered LiNi 0.5 Co 0.2 Mn 0.3 O 2 powders were obtained by the post-heat treatment of the lithiated metal oxide. The materials were characterized by X-ray diffraction (XRD), scanning electron microscope (SEM), inductively coupled plasma (ICP), atomic absorption spectroscopy (AAS), cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS) and galvanostatic charge/discharge testing. The cathode material with hexagonal α-NaFeO 2 structure, low cation mixing, appropriate crystallinity and homogeneous spherical particles was obtained. The results indicated that the initial discharge capacities of the cathode material were 150 mAh g −1 , 165.7 mAh g −1 and 184.8 mAh g −1 at the discharge rate of 0.5 C (100 mA g −1 ) with the cut-off voltage range of 3.0–4.3 V, 2.8–4.4 V and 2.5–4.5 V, respectively, and it retained 97.6%, 99.4% and 99.2% of the initial capacity after 50 cycles. It indicated that the novel hydrothermal lithiation followed by post-heat treatment is a promising route for the synthesis of LiNi 0.5 Co 0.2 Mn 0.3 O 2 cathode material with improved properties.