The synthesis and electrochemical characteristics of LiCo x Mn y Ni1−x−y O2 as cathode materials for rechargeable lithium-ion batteries were investigated. The precursor Co x Mn y Ni1−x−y (OH)2 was obtained by the chemical co-precipitation method. LiCo x Mn y Ni1−x−y O2 (0≤x≤0.3, and y=0.2) was prepared by heating a mixture of Co x Mn y Ni1−x−y (OH)2 and Li2CO3 at 850–900°C for 24h in air. The X-ray diffraction (XRD) patterns indicated that pure phase LiCo x Mn y Ni1−x−y O2 was obtained. The scanning electron micrographs (SEMs) show that the synthesized LiCo x Mn y Ni1−x−y O2 compounds have good micro-morphology and uniform particle size. The electrochemical properties of these materials such as the galvanostatic charge–discharge performance and cyclic voltammetry were systematically measured.