Abstract: A series of LiNi_0.8Co_0.15Al_0.05O₂ cathode materials were prepared at 740~820℃ by co-precipitation and high temperature solid phase method. The effect of small temperature changes on the structure and properties of the materials was investigated. The material properties were characterized by X ray analyzer, electrochemical workstation and battery charging and discharging test system. The results show that the material sintered at 780℃ has a pure hexagonal phase and is optimal in layered structure. It achieves 188.11 mAh/g at 2.75~4.2 V and 0.1 C rate. The capacity stability rate is 88.55 % after 0.5 C cycle for 100 times, which is higher than that of other temperature prepared materials. The irreversible capacity loss of materials sintered at 780℃ after different rate discharges is much lower than that of materials prepared at other temperatures.