| Abstract: LiNi1/3Co1/3Mn1/3O2 was prepared by a carbonate co-precipitation method combined with an ultrasonic technique, followed by a high temperature solid state reaction. Related characters were investigated by scanning electron macroscopy(SEM), energy dispersive spectroscopy(EDS), X-ray diffraction(XRD), differential scanning calorimetry(DSC), cyclic voltammetry(CV) and charge-discharge cycling. It′s found that the material could form a hexagonal structure (α-NaFeO2), calcined at 700～1 000 ℃ and the ordering degree of crystal increased with the increasing of calcined temperature. The particle size was about 200 nm and its distribution was uniform, as observed by SEM. Initial discharge capacity of 156.3 mAh·g-1 of LiNi1/3Co1/3Mn1/3O2 prepared at 900 ℃ was obtained between 2.8 and 4.3 V, at 0.1C-rate. The initial dischange capacity of 137.8, 129.3, 114.4, 95.5 mAh·g-1 was observed at 1C, 2C, 5C, 10C, respectively. The electrode showed good rate capability since little capacity fade appeared after 5 cycles at different rates even at 10C and 96% of initial discharge capacity was maintained after 40 cycles at 1C. Besides, thermal stability of LixNi1/3Co1/3Mn1/3O2(4.2 V) showed by DSC was better than that of LixMn2O4 and LixCoO2. |
