Li[Li 0.24 Mn 0.55 Co 0.14 Ni 0.07 ]O 2 cathode materials with controlled spherical morphology and particle size in the range of 5–10μm were synthesized by a modified co-precipitation method. The crystal structure of Li[Li 0.24 Mn 0.55 Co 0.14 Ni 0.07 ]O 2 was investigated by Rietveld analysis of structural models using X-ray and neutron powder diffraction data, indicating the presence of Li 2 MnO 3 in the final product. Li[Li 0.24 Mn 0.55 Co 0.14 Ni 0.07 ]O 2 shows low initial irreversible capacity loss (47.2mAh/g), high reversible capacity (264.6mAh/g), good capacity retention (90.4% over 50cycles) and satisfactory rate capability when used as the cathode material in lithium ion batteries. X-ray photoelectron spectroscopy analysis of the pristine, charged and discharged electrodes of Li[Li 0.24 Mn 0.55 Co 0.14 Ni 0.07 ]O 2 reveals that the Mn 4+ /Mn 3+ redox couple participates in the delithiation/lithiation process. Overall, the improved electrochemical performance of the Li[Li 0.24 Mn 0.55 Co 0.14 Ni 0.07 ]O 2 electrode can be ascribed to the controlled and specially designed morphology and the composition of the sample that is produced by the co-precipitation method.