Abstract xLi 2MnO 3·(1− x)Li(Ni 1/3Co 1/3Mn 1/3)O 2 ( x=0.25, 0.40, 0.55) compounds were prepared by low-heating solid state reaction. In the voltage range of 2.70-4.35 V, the discharge capacity of the electrode decreased with the increase of x, with a better cyclability. However, when cycled between 2.7 and 4.6 V, the cathodes delivered much larger capacities and their capacities increased with the introduction of Li 2MnO 3. Moreover, it was found that the discharge capacity gradually increased with the cycle number. The reason for this phenomenon was discussed. It was found that the relatively low cut-off potential made the activation of the Li 2MnO 3 component in the compound a gradual process, which caused the increasing capacity.