Pure Li1.1Ni0.35Co0.35Mn0.30O2 powders are also successfully synthesized by hydroxide co-precipitation method,and characterized with X-ray powder diffractometry and scanning electron microscopy.Their electrochemical properties have been studied by charge-discharge tests and cyclic voltammetry.The Li1.1Ni0.35Co0.35Mn0.30O2 powders have a typical hexagonal layered crystal structure with an average size of about 600 nm.The cathodes exhibit good cycling performance and rate capability.The initial discharge capacity of the cathodes is 154.8 mAhg-1 at 0.5 C between 2.5 and 4.3 V,and the capacity retention keeps 85.6% after 40 charge-discharge cycles.The Li1.1Ni0.35Co0.35Mn0.30O2/Li4Ti5O12 cell system also shows high specific capacity and good cycling stability.The ac impedance spectra analysis confirmed indirectly good cycle performance of the cell system.