Synthesis and Electrochemical Properties of Modification LiNi_1/3Co_1/3Mn_1/3O₂ Cathode Materials for Li-ion Battery

The layered LiNi_1/3Co_1/3Mn_1/3–x Mg _x O₂ (x = 0, 0.01, 0.03, 0.05) cathode materials were prepared by solid state reaction, then copper oxide was coated on the product. The structures, morphologies and electrochemical properties of the LiNi_1/3Co_1/3Mn_1/3–x Mg _x O₂ and CuO-coated LiNi_1/3Co_1/3Mn_1/3–x Mg _x O₂ were characterized by X-ray diffractometry (XRD), scanning electron microscopy (SEM), and electrochemical tests. The results showed that the electrochemistry properties and cycle performance of magnesium doped LiNi_1/3Co_1/3Mn_1/3O₂ and CuO-coated LiNi_1/3Co_1/3Mn_1/3–x Mg _x O₂ materials were improved. The optimal doping content of Mg was x = 0.03 in the LiNi_1/3Co_1/3Mn_1/3–x Mg _x O₂ samples to achieve high discharge capacity and good cyclic stability, and the first discharge special capacity was 158.5 mAh/g at 0.2 C in the voltage of 2.5–4.3 V, then CuO-coated LiNi_1/3Co_1/3Mn_1/3–0.03Mg_0.03O₂ was investigated. The electrode reaction reversibility and electronic conductivity were enhanced through Mg-doped and CuO-coated.