Preparation and electrochemical performance of Li[Ni_1/3Co_1/3Mn_1/3]O₂cathode material for high-rate lithium-ion batteries

A spherical Li[Ni_1/3Co_1/3Mn_1/3]O₂cathode material for lithium-ion batteries was synthesized using a combination of modified carbonate co-precipitation and solid-state methods. The as-prepared material was analyzed using X- ray diffractometry (XRD), scanning electron microscopy (SEM), galvanostatic chargedischarge tests, cyclic voltammetry (CV), and electrochemical impedance spectroscopy (EIS). The results indicate that the material synthesized using this new method has a well-ordered layered structure, α-NaFeO₂space group: R3m (166)], a spherical morphology, and an average particle size of 157 nm. Electrochemical measurements showed that the material has a good rate capability and long-term cycling performance. At a current density of 0.1C (1.0C=180mA∙g^-1) in the voltage range 2.7-4.3 V, the initial discharge capacity was 156.4 mAh∙g^-1 and the coulombic efficiency was 81.9%. At 0.5C, 5C, and 20C, the specific capacities of the material were 136.9, 111.3, and 81.3 mAh∙g^-1, respectively. After 100 cycles at 1C, the material retained 92.9% of its initial capacity; this is higher than those of materials prepared using conventional carbonate co-precipitation (87.0%).