The high voltage layered Li[Li0.2Mn0.56Ni0.16Co0.08]O2 cathode material, which is a solid solution between Li2MnO3 and LiMn0.4Ni0.4Co0.2O2, has been synthesized by co-precipitation method followed by high temperature annealing at 900°C. XRD and SEM characterizations proved that the as prepared powder is constituted of small and homogenous particles (100–300nm), which are seen to enhance the material rate capability. After the initial decay, no obvious capacity fading was observed when cycling the material at different rates. Steady-state reversible capacities of 220mAhg−1 at 0.2C, 190mAhg−1 at 1C, 155mAhg−1 at 5C and 110mAhg−1 at 20C were achieved in long-term cycle tests within the voltage cutoff limits of 2.5 and 4.8V at 20°C.