Abstract: Ni_1-2xCo_xMn_xCO₃ concentration-gradient precursor was prepared by ammonia-carbonate co-precipitation method.Then，layered LiNi_1-2xCo_xMn_xO₂ cathode materials were prepared by solid phase method at different sintering temperatures.The prepared materials were characterized by SEM and XRD,which proved they had typical layered α-NaFeO₂structure with particle size of 100~400 nm.Through LAND battery test system,the initial discharge capacities were 174.1,168.8,147,108 mA?h/g respectively at 0.5,1,2,5 C,and retained 92%, 87.5%,81.5%,and 62.3% after 30 charge-discharge cycles within the charge-discharge voltage range of 2.75~4.6 V at 20 ℃,which exhibited good rate capability.

Key words: lithium-ion batteries, concentration-gradient cathode material, carbonate co-precipitation method, rate capability