Layered oxide cathode materials Li_x(Ni_0.33Mn_0.33Co_0.33)_1-xO₂ (x=0, 0.07, 0.143 and 0.175) have been prepared by solid state reaction from a stoichiometric mixture of Li₂CO₃, NiO, Co₂O₃ and MnO₂. Starting materials were well mixed in a non-liquid state in an agate ball milling tank at 800 rpm for 270 min. The milled powder was heated at 10 ºC/min heating rate under air atmosphere first up to 400 ºC for 4 h and then up to 800 ºC for 12 h. The obtained materials were left at room temperature and ground using an agate mortar up to smaller than mesh #325.

The phase purity and crystalline structure of materials were determined by X-ray diffraction analysis and Rietveld refinements studies. Surface morphology and elemental analysis were carried out by scanning electron microscopy. Particle diameters were measured by light scattering experiments.

Electrochemical performan