Lithium non-stoichiometric Li[Li x (Ni1/3Co1/3Mn1/3)1−x ]O2 materials (0≤ x ≤0.17) were synthesized using a spray drying method. The electrochemical properties and structural stabilities of the synthesized materials were investigated. The synthesized materials exhibited a hexagonal structure in all the x-value and the lattice parameters of the materials were gradually decreased with increasing x-value due to an increasing amount of Ni3+ ions for charge compensation. The capacity retention ability and rate capability of the stoichiometric Li(Ni1/3Co1/3Mn1/3)O2 material were improved by increasing x-value, the so-called overlithiation. We found that the overlithiated materials could keep more structural integrity than the stoichiometric one during electrochemical cyclings, which could be one of reasons for a better electrochemical properties of the overlithiated materials.