Ni-rich layered LiNi0.9Co0.1O2 cathode materials have been prepared by co-precipitation and solid-state reaction, and the effect of calcination temperature and Li/M molar ratio on the structure and electrochemical performance is systematically investigated. Sample fired at 730 °C with Li/M = 1.03 provided the best structural and electrochemical performance. The optimized sample delivered 220 mAh g−1 discharge capacity at 0.1 C, and 92.5% capacity retention after 50 cycles at 1 C along with better rate capability (192 mAh g−1 discharge capacity at 2 C). Such excellent performance is possibly attributed to the uniform clean spherical particles and well-developed layered structure with low cation mixing.