Papers by Keyword: Li[Ni_1/3Co_1/3Mn_1/3]O₂

Abstract: Li[Ni1/3Co1/3Mn1/3]O2 was synthesized by modified combustion method and effect of calcination temperature on characteristics was investigated. The cycle of Li[Ni1/3Co1/3Mn1/3]O2 was determined by electrochemical measurements, the microscopic structural features were investigated using Fourier transform infrared spectroscope(FTIR), Scanning Electron Microscopy (SEM), X-ray diffraction (XRD). The results show that the compound has layered structure with hexagonal lattice. With the increase of calcination temperature, the size of primary particle rises. The Li[Ni1/3Co1/3Mn1/3]O2 calcined at 900 oC shows excellent electrochemical performances with large reversible specific capacity of 152 mAhg-1 in the voltage range of 2.75-4.20 V.

Abstract: Spherical Li[Ni(1/3-x)Mn(1/3-x)Co(1/3-x)Mx]O2 (M=Fe, Mg, Al) precursor powders were synthesized by ultrasonic spray pyrolysis using aqueous solution of metal nitrate. X-ray diffraction (XRD), scanning electron microscope (SEM), BET method using N2 adsorption analysis and Battery tester were used for determination of the composition, morphology, particle size, surface area and electrochemical properties. SEM observation showed that the size of as-prepared particles were about 0.9 μ with narrow size distribution. The crystal phase of Li[Ni(1/3-x)Mn(1/3-x)Co(1/3-x)Mx]O2 (M=Fe, Mg, Al) was resulted in layered rock salt structure with R3m space group by calcinations at 1023 K for 10 h. No impurity-related peaks are observed from the XRD pattern with various doping metals. Mg and Al doped Li(Ni1/3Co1/3Mn1/3)O2 showed very good cycling stability. The Mg substitution for Ni led to the most excellent. On the other hand, the capacity degradation during cycling was observed by Fe substitution for Mn doped Li(Ni1/3Co1/3Mn1/3)O2.

Abstract: Cathode material Li[Ni1/3Co1/3Mn1/3]O2 for lithium-ion batteries with layered hexagonal structure was successfully synthesized in sol-gel way. The influences of calcination temperature (from 700° to 1000°C) on the structure and electrochemical behaviors of Li[Ni1/3Co1/3Mn1/3]O2 were extensively investigated. The results of XRD show that all samples are isostructural with α-NaFeO2 with a space group R-3m. XPS analysis shows that the oxidation states of Co and Mn were Co3+ and Mn4+ respectively, while Ni exists as Ni2+ and Ni3+. The charge-discharge experiments show that the sample calcined at 850°C delivers 194.8mAh/g in the first cycle at C/5 rate in 2.5-4.3V potential range.

Abstract: Spherical Li
Ni1/3Mn1/3Co1/3O2 precursor powders were synthesized by aerosol plasma pyrolysis using aqueous solution of metal nitrate. XRD, SEM, TEM and BET analysis were used for determi- nation of the composition, morphology, particle size and surface area. SEM observation showed that the size of as-prepared particles were about 200 nm. The value of geometrical standard deviation (σg) calculated from the particle size distribution was 1.20, suggesting that the particle size distribution was narrow. The crystal phase of Li
Ni1/3Mn1/3Co1/3O2 was resulted in layered rock salt structure with R3m space group. The rechargeable capacity of Li
Ni1/3Mn1/3Co1/3O2 was about 142-175 mAh/g. The discharge capacity of Li
Ni1/3Mn1/3Co1/3O2 decreased with increasing cycle number. However, the cycling stability of Li(Ni1/3Mn1/3Co1/3)O2 powders that aerosol plasma pyrolysis process offered superior performance to ultrasonic spray pyrolysis process.