LiNi0.9Co0.1O2 cathode material is prepared from LiOH·H2O and Ni0.9Co0.1(OH)2 by co-precipitation and subsequent two-stage heat treatment in flowing oxygen based on the results of thermogravimetric. The structural and electrochemical properties of the samples are characterized by means of inductively coupled plasma-atomic emission spectrometer (ICP-AES), X-ray diffraction (XRD), scanning electron microscope (SEM), cyclic voltammogram (CV) and charge–discharge studies. All the samples sintered at different temperatures have a typical layered structure with space group R3-m and good electrochemical performances. The sintering temperature has a remarkable effect on the electrochemical performance of the samples. The sample sintered at 730 °C shows the largest initial discharge capacity 191.1 mAh g−1 (50 mA g−1, 3.0–4.3 V) and the best cycling performance. The initial discharge capacity rises to above 200 mAh g−1 with the voltage range 3.0–4.5 V.